A large family of proteins that have been traditionally classified as the light-harvesting proteins of the photosynthetic reaction complex. Chlorophyll binding proteins are also found in non-photosynthetic settings where they may play a photoprotective role in response to light stress.
Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.
Complexes containing CHLOROPHYLL and other photosensitive molecules. They serve to capture energy in the form of PHOTONS and are generally found as components of the PHOTOSYSTEM I PROTEIN COMPLEX or the PHOTOSYSTEM II PROTEIN COMPLEX.
A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.
Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.
Products of the hydrolysis of chlorophylls in which the phytic acid side chain has been removed and the carboxylic acids saponified.
The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)
A large multisubunit protein complex that is found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to drive electron transfer reactions that result in either the reduction of NADP to NADPH or the transport of PROTONS across the membrane.
A photo-active pigment localized in prolamellar bodies occurring within the proplastids of dark-grown bean leaves. In the process of photoconversion, the highly fluorescent protochlorophyllide is converted to chlorophyll.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
Proteins that bind to the 3' polyadenylated region of MRNA. When complexed with RNA the proteins serve an array of functions such as stabilizing the 3' end of RNA, promoting poly(A) synthesis and stimulating mRNA translation.
Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.
Any normal or abnormal coloring matter in PLANTS; ANIMALS or micro-organisms.
Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)
A phylum of oxygenic photosynthetic bacteria comprised of unicellular to multicellular bacteria possessing CHLOROPHYLL a and carrying out oxygenic PHOTOSYNTHESIS. Cyanobacteria are the only known organisms capable of fixing both CARBON DIOXIDE (in the presence of light) and NITROGEN. Cell morphology can include nitrogen-fixing heterocysts and/or resting cells called akinetes. Formerly called blue-green algae, cyanobacteria were traditionally treated as ALGAE.
Membranous cisternae of the CHLOROPLAST containing photosynthetic pigments, reaction centers, and the electron-transport chain. Each thylakoid consists of a flattened sac of membrane enclosing a narrow intra-thylakoid space (Lackie and Dow, Dictionary of Cell Biology, 2nd ed). Individual thylakoids are interconnected and tend to stack to form aggregates called grana. They are found in cyanobacteria and all plants.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Chlorophylls from which the magnesium has been removed by treatment with weak acid.
Transport proteins that carry specific substances in the blood or across cell membranes.
Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.
The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The absence of light.
A form-genus of unicellular CYANOBACTERIA in the order Chroococcales. None of the strains fix NITROGEN, there are no gas vacuoles, and sheath layers are never produced.
The general name for a group of fat-soluble pigments found in green, yellow, and leafy vegetables, and yellow fruits. They are aliphatic hydrocarbons consisting of a polyisoprene backbone.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A plant genus of the family POACEAE. The EDIBLE GRAIN, barley, is widely used as food.
Four PYRROLES joined by one-carbon units linking position 2 of one to position 5 of the next. The conjugated bond system results in PIGMENTATION.
A family of immunophilin proteins that bind to the immunosuppressive drugs TACROLIMUS (also known as FK506) and SIROLIMUS. EC 5.2.1.-
A widely cultivated plant, native to Asia, having succulent, edible leaves eaten as a vegetable. (From American Heritage Dictionary, 1982)
Phytol is a diterpene alcohol that is a degradation product of chlorophyll and is used in the synthesis of vitamins E and K and other compounds in animals, but can also act as a phytoestrogen in certain plants.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
A poly(A) binding protein that has a variety of functions such as mRNA stabilization and protection of RNA from nuclease activity. Although poly(A) binding protein I is considered a major cytoplasmic RNA-binding protein it is also found in the CELL NUCLEUS and may be involved in transport of mRNP particles.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.

Spectroscopic and molecular characterization of a long wavelength absorbing antenna of Ostreobium sp. (1/69)

One of the strains of the marine green alga Ostreobium sp. possesses an exceptionally large number of long wavelength absorbing chlorophylls (P. Haldall, Biol. Bull. 134, 1968, 411-424) as evident from a distinct shoulder in the absorption spectrum at around 710 nm while in the other strain this shoulder is absent. Therefore, Ostreobium offers a unique possibility to explore the origin of these red-shifted chlorophylls, because strains with and without these spectral forms can be compared. Here, we characterize these red forms spectroscopically by absorption, fluorescence and CD spectroscopy. In the CD spectra at least three spectroscopic red forms are identified which lead to an unusual room temperature fluorescence spectrum that peaks at 715 nm. The gel electrophoretic pattern from thylakoids of Ostreobium sp. shows an intense band at 22 kDa which correlates with the presence or absence of long wavelength absorbing pigments. By protein sequencing of the N-terminus of the 22-kDa polypeptide and sequence alignments, this was identified as an Lhca1-type light-harvesting complex. The abundance of this polypeptide - and a possibly co-migrating one - in Ostreobium sp. indicates an antenna size of approximately 340 chlorophyll molecules (Chl a and Chl b) per PS IIalpha reaction center, which is significantly larger than in higher plants ( approximately 240). The red forms are more abundant in the interior of the thalli where a 'shade-light' light field is expected than in the white-light exposed surface. This demonstrates that algae exist which may be able to up-regulate the synthesis of large amounts of LHCI and associated red forms under appropriate illumination conditions.  (+info)

Supramolecular organization of photosystem II and its light-harvesting antenna in partially solubilized photosystem II membranes. (2/69)

We present an extended analysis of the organization of green plant photosystem II and its associated light-harvesting antenna using electron microscopy and image analysis. The analysis is based on a large dataset of 16 600 projections of negatively stained PSII-LHCII supercomplexes and megacomplexes prepared by means of three different pretreatments. In addition to our previous work on this system [Boekema, E.J., van Roon, H., Calkoen, F., Bassi, R. and Dekker, J.P. (1999) Biochemistry 38, 2233-2239], the following results were obtained. The rotational orientation of trimeric LHCII at the S, M and L binding positions was determined. It was found that compared to the S trimer, the M and L trimers are rotationally shifted by about -20 degrees and -50 degrees, respectively. The number of projections with empty CP29, CP26 and CP24 binding sites was found to be about 0, 18 and 4%, respectively. We suggest that CP26 and CP24 are not required for the binding of trimeric LHCII at any of the three binding positions. A new type of megacomplex was observed with a characteristic windmill-like shape. This type III megacomplex consists of two C2S2 supercomplexes connected at their CP26 tips. Structural variation in the region of the central dimeric photosystem II complex was found to occur at one specific position near the periphery of the complex. We attribute this variation to the partial absence of an extrinsic polypeptide or one or more small intrinsic membrane proteins.  (+info)

Ultrafast excitation dynamics of low energy pigments in reconstituted peripheral light-harvesting complexes of photosystem I. (3/69)

Ultrafast dynamics of a reconstituted Lhca4 subunit from the peripheral LHCI-730 antenna of photosystem I of higher plants were probed by femtosecond absorption spectroscopy at 77 K. Intramonomeric energy transfer from chlorophyll (Chl) b to Chl a and energy equilibration between Chl a molecules observed on the subpicosecond time scale are largely similar to subpicosecond energy equilibration processes within LHCII monomers. However, a 5 ps equilibration process in Lhca4 involves unique low energy Chls in LHCI absorbing at 705 nm. These pigments localize the excitation both in the Lhca4 subunit and in LHCI-730 heterodimers. An additional 30-50 ps equilibration process involving red pigments of Lhca4 in the heterodimer, observed by transient absorption and picosecond fluorescence spectroscopy, was ascribed to intersubunit energy transfer.  (+info)

A potential role of chlorophylls b and c in assembly of light-harvesting complexes. (4/69)

Chlorophyll (Chl)-containing light-harvesting complexes (LHCs) in chloroplasts of plant and algal cells usually include an oxidized Chl (Chl b or c) in addition to Chl a. Oxidation of peripheral groups on the tetrapyrrole structure increases the Lewis acid strength of the central Mg atom. We propose that the resulting stronger coordination bonds between oxidized Chls and ligands in LHC apoproteins (LHCPs) stabilize the initial intermediates and thus promote assembly of LHCs within the chloroplast envelope.  (+info)

Antisense inhibition of the photosynthetic antenna proteins CP29 and CP26: implications for the mechanism of protective energy dissipation. (5/69)

The specific roles of the chlorophyll a/b binding proteins CP29 and CP26 in light harvesting and energy dissipation within the photosynthetic apparatus have been investigated. Arabidopsis was transformed with antisense constructs against the genes encoding the CP29 or CP26 apoprotein, which gave rise to several transgenic lines with remarkably low amounts of the antisense target proteins. The decrease in the level of CP24 protein in the CP29 antisense lines indicates a physical interaction between these complexes. Analysis of chlorophyll fluorescence showed that removal of the proteins affected photosystem II function, probably as a result of changes in the organization of the light-harvesting antenna. However, whole plant measurements showed that overall photosynthetic rates were similar to those in the wild type. Both antisense lines were capable of the qE type of nonphotochemical fluorescence quenching, although there were minor changes in the capacity for quenching and in its induction kinetics. High-light-induced violaxanthin deepoxidation to zeaxanthin was not affected, although the pool size of these pigments was decreased slightly. We conclude that CP29 and CP26 are unlikely to be sites for nonphotochemical quenching.  (+info)

The properties of the chlorophyll a/b-binding proteins Lhca2 and Lhca3 studied in vivo using antisense inhibition. (6/69)

The specific functions of the light-harvesting proteins Lhca2 and Lhca3 were studied in Arabidopsis ecotype Colombia antisense plants in which the proteins were individually repressed. The antisense effect was specific in each plant, but levels of Lhca proteins other than the targeted products were also affected. The contents of Lhca1 and Lhca4 were unaffected, but Lhca3 (in Lhca2-repressed plants) was almost completely depleted, and Lhca2 decreased to about 30% of wild-type levels in Lhca3-repressed plants. This suggests that the Lhca2 and Lhca3 proteins are in physical contact with each other and that they require each other for stability. Photosystem I fluorescence at 730 nm is thought to emanate from pigments bound to Lhca1 and Lhca4. However, fluorescence emission and excitation spectra suggest that Lhca2 and Lhca3, which fluoresce in vitro at 680 nm, also could contribute to far-red fluorescence in vivo. Spectral forms with absorption maxima at 695 and 715 nm, apparently with emission maxima at 702 and 735 nm, respectively, might be associated with Lhca2 and Lhca3.  (+info)

Biochemical properties of the PsbS subunit of photosystem II either purified from chloroplast or recombinant. (7/69)

The biochemical properties of PsbS protein, a nuclear-encoded Photosystem II subunit involved in the high energy quenching of chlorophyll fluorescence, have been studied using preparations purified from chloroplasts or obtained by overexpression in bacteria. Despite the homology with chlorophyll a/b/xanthophyll-binding proteins of the Lhc family, native PsbS protein does not show any detectable ability to bind chlorophylls or carotenoids in conditions in which Lhc proteins maintain full pigment binding. The recombinant protein, when refolded in vitro in the presence of purified pigments, neither binds chlorophylls nor xanthophylls, differently from the homologous proteins LHCII, CP26, and CP29 that refold into stable pigment-binding complexes. Thus, it is concluded that if PsbS is a pigment-binding protein in vivo, the binding mechanism must be different from that present in other Lhc proteins. Primary sequence analysis provides evidence for homology of PsbS helices I and III with the central 2-fold symmetric core of chlorophyll a/b-binding proteins. Moreover, a structural homology owed to the presence of acidic residues in each of the two lumen-exposed loops is found with the dicyclohexylcarbodiimide/Ca(2+)-binding domain of CP29. Consistently, both native and recombinant PsbS proteins showed [(14)C]dicyclohexylcarbodiimide binding, thus supporting a functional basis for its homology with CP29 on the lumen-exposed loops. This domain is suggested to be involved in sensing low luminal pH.  (+info)

Mutation analysis of Lhca1 antenna complex. Low energy absorption forms originate from pigment-pigment interactions. (8/69)

The light harvesting complex Lhca1, one of the four gene products comprising the photosystem I antenna system, has been analyzed by site-directed mutagenesis with the aim of determining the chromophore(s) responsible for its long wavelength chlorophyll spectral form, a specific characteristic of the LHCI antenna complex. A family of mutant proteins, each carrying a mutation at a single chlorophyll-binding residue, was obtained and characterized by biochemical and spectroscopic methods. A map of the chromophores bound to each of the 10 chlorophyll-binding sites was drawn, and the energy levels of the Q(y) transition were determined in most cases. When compared with Lhcb proteins previously analyzed, Lhca1 is characterized by stronger interactions between individual chromophores as detected by both biochemical and spectroscopic methods; most mutations, although targeted to a single residue, lead to the loss of more than one chromophore and of conservative CD signals typical of chlorophyll-chlorophyll interactions. The lower energy absorption form (686 nm at 100K, 688 nm at room temperature), which is responsible for the red-shifted emission components at 690 and 701 nm, typical of Lhca1, is associated with a chlorophyll a/chlorophyll a excitonic interaction originating from a pigment cluster localized in the protein domain situated between helix C and the helix A/helix B cross. This cluster includes chlorophylls bound to sites A5-B5-B6 and a xanthophyll bound to site L2.  (+info)

Chlorophyll binding proteins, also known as light-harvesting complexes (LHCs), are a type of protein found in the chloroplasts of plants, algae, and cyanobacteria. They play a crucial role in photosynthesis by binding to and helping to absorb light energy, which is then used to power the conversion of carbon dioxide and water into oxygen and glucose.

Chlorophyll binding proteins are composed of several subunits that contain both protein and chlorophyll molecules. The chlorophyll molecules are bound to the protein subunits in a way that allows them to absorb light energy most efficiently. When light is absorbed by the chlorophyll, it excites the electrons in the chlorophyll molecule, which then transfer the energy to other molecules in the photosynthetic apparatus.

There are several different types of chlorophyll binding proteins, each with slightly different properties and functions. Some are involved in capturing light energy for use in photosystem I, while others are involved in photosystem II. Additionally, some chlorophyll binding proteins are found in the thylakoid membranes of the chloroplasts, while others are located in the stroma.

Overall, chlorophyll binding proteins are essential components of the photosynthetic process, allowing plants and other organisms to harness the energy of the sun to power their metabolic reactions.

Chlorophyll is a green pigment found in the chloroplasts of photosynthetic plants, algae, and some bacteria. It plays an essential role in light-dependent reactions of photosynthesis by absorbing light energy, primarily from the blue and red parts of the electromagnetic spectrum, and converting it into chemical energy to fuel the synthesis of carbohydrates from carbon dioxide and water. The structure of chlorophyll includes a porphyrin ring, which binds a central magnesium ion, and a long phytol tail. There are several types of chlorophyll, including chlorophyll a and chlorophyll b, which have distinct absorption spectra and slightly different structures. Chlorophyll is crucial for the process of photosynthesis, enabling the conversion of sunlight into chemical energy and the release of oxygen as a byproduct.

Light-harvesting protein complexes are specialized structures in photosynthetic organisms, such as plants, algae, and some bacteria, that capture and transfer light energy to the reaction centers where the initial chemical reactions of photosynthesis occur. These complexes consist of proteins and pigments (primarily chlorophylls and carotenoids) arranged in a way that allows them to absorb light most efficiently. The absorbed light energy is then converted into electrical charges, which are transferred to the reaction centers for further chemical reactions leading to the production of organic compounds and oxygen. The light-harvesting protein complexes play a crucial role in initiating the process of photosynthesis and optimizing its efficiency by capturing and distributing light energy.

Photosystem II Protein Complex is a crucial component of the photosynthetic apparatus in plants, algae, and cyanobacteria. It is a multi-subunit protein complex located in the thylakoid membrane of the chloroplasts. Photosystem II plays a vital role in light-dependent reactions of photosynthesis, where it absorbs sunlight and uses its energy to drive the oxidation of water molecules into oxygen, electrons, and protons.

The protein complex consists of several subunits, including the D1 and D2 proteins, which form the reaction center, and several antenna proteins that capture light energy and transfer it to the reaction center. Photosystem II also contains various cofactors, such as pigments (chlorophylls and carotenoids), redox-active metal ions (manganese and calcium), and quinones, which facilitate the charge separation and electron transfer processes during photosynthesis.

Photosystem II Protein Complex is responsible for the initial charge separation event in photosynthesis, which sets off a series of redox reactions that ultimately lead to the reduction of NADP+ to NADPH and the synthesis of ATP, providing energy for the carbon fixation reactions in the Calvin cycle. Additionally, Photosystem II Protein Complex is involved in oxygen evolution, contributing to the Earth's atmosphere's oxygen levels and making it an essential component of global carbon fixation and oxygen production.

Photosynthetic Reaction Center (RC) Complex Proteins are specialized protein-pigment structures that play a crucial role in the primary process of light-driven electron transport during photosynthesis. They are present in the thylakoid membranes of cyanobacteria, algae, and higher plants.

The Photosynthetic Reaction Center Complex Proteins are composed of two major components: the light-harvesting complex (LHC) and the reaction center (RC). The LHC contains antenna pigments like chlorophylls and carotenoids that absorb sunlight and transfer the excitation energy to the RC. The RC is a multi-subunit protein complex containing cofactors such as bacteriochlorophyll, pheophytin, quinones, and iron-sulfur clusters.

When a photon of light is absorbed by the antenna pigments in the LHC, the energy is transferred to the RC, where it initiates a charge separation event. This results in the transfer of an electron from a donor molecule to an acceptor molecule, creating a flow of electrical charge and generating a transmembrane electrochemical gradient. The energy stored in this gradient is then used to synthesize ATP and reduce NADP+, which are essential for carbon fixation and other metabolic processes in the cell.

In summary, Photosynthetic Reaction Center Complex Proteins are specialized protein structures involved in capturing light energy and converting it into chemical energy during photosynthesis, ultimately driving the synthesis of ATP and NADPH for use in carbon fixation and other metabolic processes.

Chlorophyllides are the breakdown products of chlorophyll, which is the green pigment found in plants and algae that is essential for photosynthesis. Chlorophyllides are formed when chlorophyll is broken down by enzymes or through other chemical processes. They differ from chlorophyll in that they lack a phytol tail, which is a long hydrocarbon chain that is attached to the chlorophyll molecule.

Chlorophyllides have been studied for their potential health benefits, as they are thought to have antioxidant and anti-inflammatory properties. Some research has suggested that chlorophyllides may help protect against certain types of cancer, improve immune function, and reduce the risk of heart disease. However, more research is needed to confirm these potential benefits and to determine the optimal dosages and methods for consuming chlorophyllides.

It's worth noting that chlorophyllides are not typically found in significant quantities in the diet, as they are primarily produced during the breakdown of chlorophyll in plants. However, some supplements and green superfood powders may contain chlorophyllides or chlorophyllin, which is a semi-synthetic form of chlorophyll that is more stable and easier to absorb than natural chlorophyll.

Photosynthesis is not strictly a medical term, but it is a fundamental biological process with significant implications for medicine, particularly in understanding energy production in cells and the role of oxygen in sustaining life. Here's a general biological definition:

Photosynthesis is a process by which plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy in the form of organic compounds, such as glucose (or sugar), using water and carbon dioxide. This process primarily takes place in the chloroplasts of plant cells, specifically in structures called thylakoids. The overall reaction can be summarized as:

6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

In this equation, carbon dioxide (CO2) and water (H2O) are the reactants, while glucose (C6H12O6) and oxygen (O2) are the products. Photosynthesis has two main stages: the light-dependent reactions and the light-independent reactions (Calvin cycle). The light-dependent reactions occur in the thylakoid membrane and involve the conversion of light energy into ATP and NADPH, which are used to power the Calvin cycle. The Calvin cycle takes place in the stroma of chloroplasts and involves the synthesis of glucose from CO2 and water using the ATP and NADPH generated during the light-dependent reactions.

Understanding photosynthesis is crucial for understanding various biological processes, including cellular respiration, plant metabolism, and the global carbon cycle. Additionally, research into artificial photosynthesis has potential applications in renewable energy production and environmental remediation.

Photosystem I Protein Complex, also known as PsaA/B-Protein or Photosystem I reaction center, is a large protein complex found in the thylakoid membrane of plant chloroplasts and cyanobacteria. It plays a crucial role in light-dependent reactions of photosynthesis, where it absorbs light energy and converts it into chemical energy in the form of NADPH.

The complex is composed of several subunits, including PsaA and PsaB, which are the core components that bind to chlorophyll a and bacteriochlorophyll a pigments. These pigments absorb light energy and transfer it to the reaction center, where it is used to drive the electron transport chain and generate a proton gradient across the membrane. This gradient is then used to produce ATP, which provides energy for the carbon fixation reactions in photosynthesis.

Photosystem I Protein Complex is also involved in cyclic electron flow, where electrons are recycled within the complex to generate additional ATP without producing NADPH. This process helps regulate the balance between ATP and NADPH production in the chloroplast and optimizes the efficiency of photosynthesis.

Protochlorophyllide is a pigment involved in the process of photosynthesis. It is a precursor to chlorophyll, which is the main pigment responsible for light absorption during photosynthesis. Protochlorophyllide is present in the chloroplasts of plant cells and certain types of algae. It is converted to chlorophyllide by the action of light during the process of photoactivation, which is the activation of a chemical reaction by light. Defects in the biosynthesis of protochlorophyllide can lead to certain types of genetic disorders that affect photosynthesis and plant growth.

In the context of medical terminology, "light" doesn't have a specific or standardized definition on its own. However, it can be used in various medical terms and phrases. For example, it could refer to:

1. Visible light: The range of electromagnetic radiation that can be detected by the human eye, typically between wavelengths of 400-700 nanometers. This is relevant in fields such as ophthalmology and optometry.
2. Therapeutic use of light: In some therapies, light is used to treat certain conditions. An example is phototherapy, which uses various wavelengths of ultraviolet (UV) or visible light for conditions like newborn jaundice, skin disorders, or seasonal affective disorder.
3. Light anesthesia: A state of reduced consciousness in which the patient remains responsive to verbal commands and physical stimulation. This is different from general anesthesia where the patient is completely unconscious.
4. Pain relief using light: Certain devices like transcutaneous electrical nerve stimulation (TENS) units have a 'light' setting, indicating lower intensity or frequency of electrical impulses used for pain management.

Without more context, it's hard to provide a precise medical definition of 'light'.

Chloroplasts are specialized organelles found in the cells of green plants, algae, and some protists. They are responsible for carrying out photosynthesis, which is the process by which these organisms convert light energy from the sun into chemical energy in the form of organic compounds, such as glucose.

Chloroplasts contain the pigment chlorophyll, which absorbs light energy from the sun. They also contain a system of membranes and enzymes that convert carbon dioxide and water into glucose and oxygen through a series of chemical reactions known as the Calvin cycle. This process not only provides energy for the organism but also releases oxygen as a byproduct, which is essential for the survival of most life forms on Earth.

Chloroplasts are believed to have originated from ancient cyanobacteria that were engulfed by early eukaryotic cells and eventually became integrated into their host's cellular machinery through a process called endosymbiosis. Over time, chloroplasts evolved to become an essential component of plant and algal cells, contributing to their ability to carry out photosynthesis and thrive in a wide range of environments.

Biological pigments are substances produced by living organisms that absorb certain wavelengths of light and reflect others, resulting in the perception of color. These pigments play crucial roles in various biological processes such as photosynthesis, vision, and protection against harmful radiation. Some examples of biological pigments include melanin, hemoglobin, chlorophyll, carotenoids, and flavonoids.

Melanin is a pigment responsible for the color of skin, hair, and eyes in animals, including humans. Hemoglobin is a protein found in red blood cells that contains a porphyrin ring with an iron atom at its center, which gives blood its red color and facilitates oxygen transport. Chlorophyll is a green pigment found in plants, algae, and some bacteria that absorbs light during photosynthesis to convert carbon dioxide and water into glucose and oxygen. Carotenoids are orange, yellow, or red pigments found in fruits, vegetables, and some animals that protect against oxidative stress and help maintain membrane fluidity. Flavonoids are a class of plant pigments with antioxidant properties that have been linked to various health benefits.

I believe there may be a slight misunderstanding in your question. "Plant leaves" are not a medical term, but rather a general biological term referring to a specific organ found in plants.

Leaves are organs that are typically flat and broad, and they are the primary site of photosynthesis in most plants. They are usually green due to the presence of chlorophyll, which is essential for capturing sunlight and converting it into chemical energy through photosynthesis.

While leaves do not have a direct medical definition, understanding their structure and function can be important in various medical fields, such as pharmacognosy (the study of medicinal plants) or environmental health. For example, certain plant leaves may contain bioactive compounds that have therapeutic potential, while others may produce allergens or toxins that can impact human health.

Cyanobacteria, also known as blue-green algae, are a type of bacteria that obtain their energy through photosynthesis, similar to plants. They can produce oxygen and contain chlorophyll a, which gives them a greenish color. Some species of cyanobacteria can produce toxins that can be harmful to humans and animals if ingested or inhaled. They are found in various aquatic environments such as freshwater lakes, ponds, and oceans, as well as in damp soil and on rocks. Cyanobacteria are important contributors to the Earth's oxygen-rich atmosphere and play a significant role in the global carbon cycle.

Thylakoids are membrane-bound structures located in the chloroplasts of plant cells and some protists. They are the site of the light-dependent reactions of photosynthesis, where light energy is converted into chemical energy in the form of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). Thylakoids have a characteristic stacked or disc-like structure, called grana, and are interconnected by unstacked regions called stroma lamellae. The arrangement of thylakoids in grana increases the surface area for absorption of light energy, allowing for more efficient photosynthesis.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Pheophytins are pigments that are formed when the magnesium ion is lost from chlorophylls, which are the green pigments involved in photosynthesis. This results in the conversion of chlorophyll a and chlorophyll b to pheophytin a and pheophytin b, respectively. Pheophytins do not participate in light absorption during photosynthesis and have a different spectral absorption pattern compared to chlorophylls. They are believed to play a role in the photoprotection of photosystem II by dissipating excess energy absorbed by the antenna complexes as heat, thereby preventing the formation of harmful reactive oxygen species.

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

"Plant proteins" refer to the proteins that are derived from plant sources. These can include proteins from legumes such as beans, lentils, and peas, as well as proteins from grains like wheat, rice, and corn. Other sources of plant proteins include nuts, seeds, and vegetables.

Plant proteins are made up of individual amino acids, which are the building blocks of protein. While animal-based proteins typically contain all of the essential amino acids that the body needs to function properly, many plant-based proteins may be lacking in one or more of these essential amino acids. However, by consuming a variety of plant-based foods throughout the day, it is possible to get all of the essential amino acids that the body needs from plant sources alone.

Plant proteins are often lower in calories and saturated fat than animal proteins, making them a popular choice for those following a vegetarian or vegan diet, as well as those looking to maintain a healthy weight or reduce their risk of chronic diseases such as heart disease and cancer. Additionally, plant proteins have been shown to have a number of health benefits, including improving gut health, reducing inflammation, and supporting muscle growth and repair.

Fluorescence is not a medical term per se, but it is widely used in the medical field, particularly in diagnostic tests, medical devices, and research. Fluorescence is a physical phenomenon where a substance absorbs light at a specific wavelength and then emits light at a longer wavelength. This process, often referred to as fluorescing, results in the emission of visible light that can be detected and measured.

In medical terms, fluorescence is used in various applications such as:

1. In-vivo imaging: Fluorescent dyes or probes are introduced into the body to highlight specific structures, cells, or molecules during imaging procedures. This technique can help doctors detect and diagnose diseases such as cancer, inflammation, or infection.
2. Microscopy: Fluorescence microscopy is a powerful tool for visualizing biological samples at the cellular and molecular level. By labeling specific proteins, nucleic acids, or other molecules with fluorescent dyes, researchers can observe their distribution, interactions, and dynamics within cells and tissues.
3. Surgical guidance: Fluorescence-guided surgery is a technique where surgeons use fluorescent markers to identify critical structures such as blood vessels, nerves, or tumors during surgical procedures. This helps ensure precise and safe surgical interventions.
4. Diagnostic tests: Fluorescence-based assays are used in various diagnostic tests to detect and quantify specific biomarkers or analytes. These assays can be performed using techniques such as enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), or flow cytometry.

In summary, fluorescence is a physical process where a substance absorbs and emits light at different wavelengths. In the medical field, this phenomenon is harnessed for various applications such as in-vivo imaging, microscopy, surgical guidance, and diagnostic tests.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

I am not aware of a medical definition for the term "darkness." In general, darkness refers to the absence of light. It is not a term that is commonly used in the medical field, and it does not have a specific clinical meaning. If you have a question about a specific medical term or concept, I would be happy to try to help you understand it.

I'm sorry for any confusion, but "Synechocystis" is not a medical term. It is actually a genus of cyanobacteria (also known as blue-green algae), which are gram-negative bacteria capable of photosynthesis. The most studied species, Synechocystis sp. PCC 6803, is often used as a model organism in research related to photosynthesis, carbon metabolism, and bioenergy.

If you have any medical terms or concepts that you would like me to define or explain, please let me know!

Carotenoids are a class of pigments that are naturally occurring in various plants and fruits. They are responsible for the vibrant colors of many vegetables and fruits, such as carrots, pumpkins, tomatoes, and leafy greens. There are over 600 different types of carotenoids, with beta-carotene, alpha-carotene, lycopene, lutein, and zeaxanthin being some of the most well-known.

Carotenoids have antioxidant properties, which means they can help protect the body's cells from damage caused by free radicals. Some carotenoids, such as beta-carotene, can be converted into vitamin A in the body, which is important for maintaining healthy vision, skin, and immune function. Other carotenoids, such as lycopene and lutein, have been studied for their potential role in preventing chronic diseases, including cancer and heart disease.

In addition to being found in plant-based foods, carotenoids can also be taken as dietary supplements. However, it is generally recommended to obtain nutrients from whole foods rather than supplements whenever possible, as food provides a variety of other beneficial compounds that work together to support health.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

I'm sorry for any confusion, but "Hordeum" is not a medical term. It is actually the genus name for barley in botany. If you have any medical terms or concepts that you would like me to explain, please let me know!

Tetrapyrroles are a class of organic compounds that contain four pyrrole rings joined together in a macrocyclic structure. They are important in biology because they form the core structure of many essential cofactors and prosthetic groups in proteins, including heme, chlorophyll, and cobalamin (vitamin B12).

Heme is a tetrapyrrole that contains iron and is a crucial component of hemoglobin, the protein responsible for oxygen transport in red blood cells. Chlorophyll is another tetrapyrrole that contains magnesium and plays a vital role in photosynthesis, the process by which plants convert light energy into chemical energy. Cobalamin contains cobalt and is essential for DNA synthesis, fatty acid metabolism, and neurotransmitter synthesis.

Abnormalities in tetrapyrrole biosynthesis can lead to various diseases, such as porphyrias, which are characterized by the accumulation of toxic intermediates in the heme biosynthetic pathway.

Tacrolimus binding proteins, also known as FK506 binding proteins (FKBPs), are a group of intracellular proteins that bind to the immunosuppressive drug tacrolimus (also known as FK506) and play a crucial role in its mechanism of action. Tacrolimus is primarily used in organ transplantation to prevent rejection of the transplanted organ.

FKBPs are a family of peptidyl-prolyl cis-trans isomerases (PPIases) that catalyze the conversion of proline residues from their cis to trans conformations in proteins, thereby regulating protein folding and function. FKBP12, a member of this family, has a high affinity for tacrolimus and forms a complex with it upon entry into the cell.

The formation of the tacrolimus-FKBP12 complex inhibits calcineurin, a serine/threonine phosphatase that plays a critical role in T-cell activation. Calcineurin inhibition prevents the dephosphorylation and nuclear translocation of the transcription factor NFAT (nuclear factor of activated T-cells), thereby blocking the expression of genes involved in T-cell activation, proliferation, and cytokine production.

In summary, tacrolimus binding proteins are intracellular proteins that bind to tacrolimus and inhibit calcineurin, leading to the suppression of T-cell activation and immune response, which is essential in organ transplantation and other immunological disorders.

"Spinacia oleracea" is the scientific name for a plant species, not a medical term. It is commonly known as spinach, a leafy green vegetable. While spinach has many health benefits and is often recommended as part of a balanced diet, it does not have a specific medical definition.

Spinach is rich in various nutrients such as iron, calcium, vitamin A, vitamin C, and folic acid. It can contribute to overall health, support immune function, and provide antioxidant benefits. However, it is important to note that 'Spinacia oleracea' itself does not have a medical definition.

Phytol is not a medical term, but rather a chemical compound. It is a diterpene alcohol that is a breakdown product of chlorophyll and is found in green plants. It is used in the synthesis of various compounds, including vitamins E and K, and is also used in the production of perfumes and fragrances. In the context of human health, phytol has been studied for its potential anti-cancer properties.

'Arabidopsis' is a genus of small flowering plants that are part of the mustard family (Brassicaceae). The most commonly studied species within this genus is 'Arabidopsis thaliana', which is often used as a model organism in plant biology and genetics research. This plant is native to Eurasia and Africa, and it has a small genome that has been fully sequenced. It is known for its short life cycle, self-fertilization, and ease of growth, making it an ideal subject for studying various aspects of plant biology, including development, metabolism, and response to environmental stresses.

I apologize for any confusion, but "plants" is not a term that has a medical definition. The term "plants" refers to a large and diverse group of organisms that obtain their energy through photosynthesis, which is the process of converting sunlight into chemical energy. Plants are typically characterized by having cells with cell walls containing cellulose, chloroplasts containing the pigment chlorophyll, and the ability to synthesize their own food through photosynthesis.

In a medical or biological context, you might be thinking of "plant-based" or "phytomedicine," which refer to the use of plants or plant extracts as a form of medicine or treatment. Phytomedicines have been used for thousands of years in many traditional systems of medicine, and some plant-derived compounds have been found to have therapeutic benefits in modern medicine as well. However, "plants" itself does not have a medical definition.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

"Energy transfer" is a general term used in the field of physics and physiology, including medical sciences, to describe the process by which energy is passed from one system, entity, or location to another. In the context of medicine, energy transfer often refers to the ways in which cells and organ systems exchange and utilize various forms of energy for proper functioning and maintenance of life.

In a more specific sense, "energy transfer" may refer to:

1. Bioenergetics: This is the study of energy flow through living organisms, including the conversion, storage, and utilization of energy in biological systems. Key processes include cellular respiration, photosynthesis, and metabolic pathways that transform energy into forms useful for growth, maintenance, and reproduction.
2. Electron transfer: In biochemistry, electrons are transferred between molecules during redox reactions, which play a crucial role in energy production and consumption within cells. Examples include the electron transport chain (ETC) in mitochondria, where high-energy electrons from NADH and FADH2 are passed along a series of protein complexes to generate an electrochemical gradient that drives ATP synthesis.
3. Heat transfer: This is the exchange of thermal energy between systems or objects due to temperature differences. In medicine, heat transfer can be relevant in understanding how body temperature is regulated and maintained, as well as in therapeutic interventions such as hyperthermia or cryotherapy.
4. Mechanical energy transfer: This refers to the transmission of mechanical force or motion from one part of the body to another. For instance, muscle contractions generate forces that are transmitted through tendons and bones to produce movement and maintain posture.
5. Radiation therapy: In oncology, ionizing radiation is used to treat cancer by transferring energy to malignant cells, causing damage to their DNA and leading to cell death or impaired function.
6. Magnetic resonance imaging (MRI): This non-invasive diagnostic technique uses magnetic fields and radio waves to excite hydrogen nuclei in the body, which then release energy as they return to their ground state. The resulting signals are used to generate detailed images of internal structures and tissues.

In summary, "energy transfer" is a broad term that encompasses various processes by which different forms of energy (thermal, mechanical, electromagnetic, etc.) are exchanged or transmitted between systems or objects in the context of medicine and healthcare.

... is bound to proteins. Protochlorophyllide, one of the biosynthetic intermediates, occurs mostly in the free form ... Structures of chlorophylls chlorophyll a chlorophyll b chlorophyll c1 chlorophyll c2 chlorophyll d chlorophyll f Chlorophyll e ... Chen M (2019). "Chlorophylls d and f: Synthesis, occurrence, light-harvesting, and pigment organization in chlorophyll-binding ... Unlike hemes, which contain iron bound to the N4 center, most chlorophylls bind magnesium. The axial ligands attached to the ...
This family also includes the iron-stress induced chlorophyll-binding protein CP43', encoded by the IsiA gene, which evolved in ... "Supramolecular organization and dual function of the IsiA chlorophyll-binding protein in cyanobacteria". Biochemistry. 43 (32 ... Photosystem II light-harvesting proteins are the intrinsic transmembrane proteins CP43 (PsbC) and CP47 (PsbB) occurring in the ... These polypeptides bind to chlorophyll a and β-Carotene and pass the excitation energy on to the reaction centre. ...
Universal protein resource accession number Q55274 for "Iron stress-induced chlorophyll-binding protein" at UniProt. (Protein ... is a photosynthesis-related chlorophyll-containing protein found in cyanobacteria. It belongs to the chlorophyll-a/b-binding ... Havaux M, Guedeney G, Hagemann M, Yeremenko N, Matthijs HC, Jeanjean R (April 2005). "The chlorophyll-binding protein IsiA is ... "Aggregates of the chlorophyll-binding protein IsiA (CP43') dissipate energy in cyanobacteria" (PDF). Biochemistry. 44 (32): ...
... binds to a protein of the photosystem II complex, which blocks the electron transport. The result are multiple ... First triplet-state chlorophyll reacts with oxygen to form singlet oxygen. Both chlorophyll and singlet oxygen then remove ... Triazines like hexazinone can bind to the D-1 quinone protein of the electron transport chain in photosystem II to inhibit the ... This will result in a loss of chlorophyll, leakage of cellular contents, cell death, and eventually death of the plant. Woody ...
... is a soluble molecular complex consisting of the peridinin-chlorophyll a-protein bound to peridinin, chlorophyll, and lipids. ... "The unique photophysical properties of the Peridinin-Chlorophyll-α-Protein". Current Protein & Peptide Science. 15 (4): 332-50 ... Jiang J, Zhang H, Kang Y, Bina D, Lo CS, Blankenship RE (July 2012). "Characterization of the peridinin-chlorophyll a-protein ... Each eight-helix segment typically binds four peridinin molecules, one chlorophyll a molecule, and one lipid molecule such as ...
... and a membrane-bound chlorophyll a-chlorophyll c2-peridinin-protein-complex (acpPC), along with typical photosynthetic electron ... "Isolation and Characterization of Three Membrane-Bound Chlorophyll-Protein Complexes from Four Dinoflagellate Species". ... The Unique Photophysical Properties of the Peridinin-Chlorophyll-a-Protein. In: Current Protein & Peptide Science, volume 15, ... Spectroscopic properties of the Chlorophyll a-Chlorophyll c2-Peridinin-Protein-Complex (acpPC) from the coral symbiotic ...
Chlorophyll itself is bound to proteins and can transfer the absorbed energy in the required direction. Protochlorophyllide, ... It is currently not known which other proteins interact through this linker. The regulatory protein is a transmembrane protein ... Flu (first described in ) is a nuclear-encoded, chloroplast-located protein that appears containing only protein-protein ... The FLP proteins act as regulators of chlorophyll synthesis in response to light and plastid signals in Chlamydomonas. Genes & ...
They bind to the Qb site on the D1 protein, and prevent quinone from binding to this site. Therefore, this group of compounds ... If this happens, the plants turn white due to complete loss of chlorophyll, and the plants die. Mesotrione and sulcotrione are ... This reduces or neutralizes the ability of the herbicide to bind to its target protein. The mutation may relate to an enzyme ... The term target-site cross-resistance is used when the herbicides bind to the same target site, whereas non-target-site cross- ...
The D1 protein forms the reaction center of photosystem II and is important as it binds chlorophyll. By mutating and thus ... Instead, Crocosphaera watsonii uses pstS, a protein that has a high affinity to bind to phosphorus. During times of phosphorus ... These include genes encoding the proteins nifH, nifX, glutamate synthetase, ntcA, glnB-like proteins and glgP, all of which ... Furthermore, genes encoding for photosynthetic proteins such as photosystem I subunit VII (psaC), the photosystem II D1 protein ...
Sheen, J. Y.; Bogorad, L. (1986-10-01). "Differential expression of six light-harvesting chlorophyll a/b binding protein genes ... Sheen, Jen; Hwang, Seongbin; Niwa, Yasuo; Kobayashi, Hirokazu; Galbraith, David W. (1995). "Green-fluorescent protein as a new ... and Sheen has developed the use of green fluorescent protein in higher plant research. Sheen has used the plant protoplast ... "Functional analysis of oxidative stress-activated mitogen-activated protein kinase cascade in plants". Proceedings of the ...
... s are formed of a complex between proteins and covalently bound phycobilins that act as chromophores (the light ... which is then passed on to chlorophylls during photosynthesis. ... RCSB Protein Data Bank (PDB). doi:10.2210/pdb1eyx/pdb. PDB ID: ... Phycobiliproteins are water-soluble proteins present in cyanobacteria and certain algae (rhodophytes, cryptomonads, ... RCSB Protein Data Bank (PDB). doi:10.2210/pdb3v57/pdb. PDB ID: 3V57. Retrieved 12 October 2012. {{cite journal}}: Cite journal ...
mRNAs that encode chlorophyll binding proteins and the enzyme protoporphyrin IX magnesium chelatase involved in chlorophyll ... allowing for timely synthesis of light-harvesting complex proteins and chlorophyll. Therefore, the competitive advantage in A. ...
... fucoxanthin is protein-bound along with chlorophyll to form a light harvesting protein complex. Fucoxanthin is the dominant ... of the energy transfer to chlorophyll a in diatoms When bound to protein, the absorption spectrum of fucoxanthin expands from ... "The charge-transfer properties of the S2 state of fucoxanthin in solution and in fucoxanthin chlorophyll-a/c2 protein (FCP) ... "Spectroscopic characterization of the excitation energy transfer in the fucoxanthin-chlorophyll protein of diatoms". ...
... folding in proteins, and protein stability. Apomyoglobin found in sperm whales binds pigments similar to chlorophyll, while its ... Apomyoglobin is produced in the sarcoplasm and is stated as being a hydrophilic protein. This means that the protein has a high ... Apomyoglobin is an ideal protein to take into consideration when looking at folding in proteins. This is because it has no ... pointed towards the destabilization of apomyoglobin and a decrease in the rate of the protein's binding with heme. This further ...
It is made up of four proteins: Lhca1, Lhca2, Lhca3, and Lhca4, all of which belong to the LHC or chlorophyll a/b-binding ... The N-terminus of the chlorophyll a-b binding protein extends into the stroma where it is involved with adhesion of granal ... "The N-terminal domain of the light-harvesting chlorophyll a/b-binding protein complex (LHCII) is essential for its acclimative ... The light-harvesting complex (or antenna complex; LH or LHC) is an array of protein and chlorophyll molecules embedded in the ...
The chlorophyll a/b-binding protein gene, otherwise known as the CAB gene, is one of the most thoroughly characterized clock- ... The Cab gene, responsible for encoding the chlorophyll a/b-binding protein in Arabidopsis, plays a crucial role in the ... "Light-harvesting chlorophyll a/b-binding proteins, positively involved in abscisic acid signaling, require a transcription ... A protein called CAB GATA factor 1 (CGT-1) binds to the GATA repeats and promotes CAB2 production. A mutation that prevents CGT ...
... cyanobacteria that contain both chlorophyll a and b bound to a special light-harvesting protein. Surprisingly, unlike most ... and chlorophyll-protein composition of Prochloron sp., a prokaryotic green alga". Proceedings of the National Academy of ... "Independent evolution of the prochlorophyte and green plant chlorophyll a/b light-harvesting proteins". Proceedings of the ... "Microenvironmental Ecology of the chlorophyll b-containing Symbiotic Cyanabacterium Prochloron in the Didemnid Ascidian ...
The amount of vitamin A leaving the liver, bound to retinol binding protein (RBP), is under tight control as long as there are ... Carotenoid pigments may be masked by chlorophylls in dark green leaf vegetables, such as spinach. The relatively low ... Within the cell, retinol is there bound to retinol binding protein 2 (RBP2). It is then enzymatically reesterified by the ... bind retinol to retinol-binding protein 4 (RBP4), and transfer the retinol-RBP4 to HSCs for storage in lipid droplets as ...
Protein energy malnutrition is often seen in VAD; suppressed synthesis of retinol binding protein (RBP) due to protein ... Carotenoid pigments may be masked by chlorophylls in dark green leaf vegetables, such as spinach. The relatively low ... Rhodopsin is found in the retina and is composed of retinal (an active form of vitamin A) and opsin (a protein). Night ... Retinoic acid is a ligand for nuclear retinoic acid receptors that bind the promoter regions of specific genes, thus activating ...
Light-harvesting chlorophyll a/b-binding (LHCB) protein sequences from Lemna gibba were low in darkness but could be rapidly ... Using a DNA fragment, they screened the Arabidopsis expression library, and cloned a protein with relevant binding activity, ... In a series of experiments beginning in 1993, Tobin's lab described DNA-binding activity with an affinity for LHCB in plant ... Tobin's group also demonstrated phytochrome regulation of LHCB proteins (also known as cab genes) in Arabidopsis. By growing ...
It occurs in proteins that are part of signal transduction processes and functions as a receiver of phosphate groups that are ... In chloroplasts (photosystem II), it acts as an electron donor in the reduction of oxidized chlorophyll. In this process, it ... or may form part of a signaling cascade via SH2 domain binding. A tyrosine residue also plays an important role in ... Tyrosine, which can also be synthesized in the body from phenylalanine, is found in many high-protein food products such as ...
"Molecular mechanism of Thioflavin-T binding to amyloid fibrils". Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics ... Fluorometers are widely used in oceanography to measure chlorophyll concentrations based on chlorophyll fluorescence by ... Chlorophyll fluorescence is a widely-used proxy for the quantity (biomass) of microscopic algae in the water. In the lab after ... Ocean chlorophyll fluorescence is measured on research vessels, small boats, buoys, docks, and piers all over the world. ...
Non-specific binding to the plates is reduced through the use of buffers containing proteins such as casein and non-ionic ... lower chlorophyll levels and differential activity of soluble and ionically-bound peroxidases were detected. At later stages of ... P3 Protein), 6K1 (6-kDa Protein 1), CI (Cylindrical Inclusion), 6K2 (6-kDa Protein 2), VPg (Viral Protein genome-linked), ... Nonspecifically bound components are less strongly bound than the specific bound ones. Detection is achieved either through the ...
... the light harvesting pigments of the plastidial chloroplasts are phycobiliproteins and chlorophyll a/c-binding proteins, ... as well as DNA replication proteins and protein kinases associated with cell replication. The transfer of these genes to the ... While many plastidial proteins remain in the nucleomorph, those that underwent endosymbiotic gene transfer to the host nucleus ... It is clear that the nucleomorph has been significantly reduced in size and almost entirely relies on protein targeting to the ...
Synthetic coordination compounds are also used to bind to proteins and especially nucleic acids (e.g. anticancer drug cisplatin ... Example: hemoglobin contains heme, a porphyrin complex of iron Example: chlorophyll contains a porphyrin complex of magnesium ... the ions would bind via the ammonia chains Blomstrand had described or the ions would bind directly to the metal. It was not ... Some metal complexes are formed virtually irreversibly and many are bound together by bonds that are quite strong. The number ...
Ions diffusing outwards across the gradient through proton pumps are then bound to ATP synthase proteins on the cell's surface ... However, unlike all photoautotrophs, retinalophototrophs do not use chlorophyll or an electron transport chain to power their ... A retinalophototroph is one of two different types of phototrophs, and are named for retinal-binding proteins (microbial ... one gene for retinal-binding protein synthesis (bop) and one for retinal chromophore synthesis (blh). Despite their apparent ...
Most metal complexes in the environment and in nature are bound in some form of chelate ring (e.g., with a humic acid or a ... Fe3+ chelation with the Dopa residues in mussel foot protein-1 to improve the strength of the threads that they use to secure ... Such chelating agents include the porphyrin rings in hemoglobin and chlorophyll. Many microbial species produce water-soluble ... EDTA, which binds to calcium, is used to alleviate the hypercalcemia that often results from band keratopathy. The calcium may ...
... give rise to electron transfer reactions along the path of a series of protein-bound co-factors. These co-factors are light- ... The pair of chlorophyll molecules at the reaction center are often referred to as P680. When the photon has been absorbed, the ... The tightly bound molecule is shown above the pheophytin molecule and is colored red. The loosely bound molecule is to the left ... This pair of chlorophyll molecules, often called the "special pair", absorbs photons at 870 nm or 960 nm, depending on the ...
Fa and Fb are bound to protein subunits of the PSI complex and Fx is tied to the PSI complex. Various experiments have shown ... The antenna complex is composed of molecules of chlorophyll and carotenoids mounted on two proteins. These pigment molecules ... Two main subunits of PSI, PsaA and PsaB, are closely related proteins involved in the binding of the vital electron transfer ... The Ycf4 protein domain found on the thylakoid membrane is vital to photosystem I. This thylakoid transmembrane protein helps ...
October 2021). "Structural basis of bilin binding by the chlorophyll biosynthesis regulator GUN4". Protein Science. 30 (10): ... Bilin-binding protein is a member of the lipocalin family, which includes extracellular proteins with a number of molecular ... The bilin-binding protein is predominantly present in hemolymph, fat body, and epidermis in the last instar larval and in the ... The bilin-binding protein from Pieris brassicae, which was discovered to have a crystal structure, was one of the initial ...
Chlorophyll is bound to proteins. Protochlorophyllide, one of the biosynthetic intermediates, occurs mostly in the free form ... Structures of chlorophylls chlorophyll a chlorophyll b chlorophyll c1 chlorophyll c2 chlorophyll d chlorophyll f Chlorophyll e ... Chen M (2019). "Chlorophylls d and f: Synthesis, occurrence, light-harvesting, and pigment organization in chlorophyll-binding ... Unlike hemes, which contain iron bound to the N4 center, most chlorophylls bind magnesium. The axial ligands attached to the ...
Differential expression of a chlorophyll a/b binding protein gene and a proline rich protein gene in juvenile and mature phase ... Dive into the research topics of Differential expression of a chlorophyll a/b binding protein gene and a proline rich protein ...
... vivo binding targets and binding landscapes represents a gap in understanding the mode of action of plant RNA-binding proteins ... wide to determine the binding repertoire of the circadian clock-regulated Arabidopsis thaliana glycine-rich RNA-binding protein ... We have established iCLIP for plants to identify target transcripts of the RNA-binding protein AtGRP7. This paves the way to ... AtGRP7 can bind to all transcript regions, with a preference for 3′ untranslated regions. In the vicinity of crosslink sites, U ...
chlorophyll binding [ISS]. Gene Ontology Cellular Component. *chloroplast [IDA, ISM]*chloroplast envelope [IDA]*chloroplast ... Search BioGRID for SARS-CoV-2 Protein Interactions , Download SARS-CoV-2 and Coronavirus-Related Interactions ... F15L11.2, F15L11_2, LHCB2, LIGHT-HARVESTING CHLOROPHYLL B-BINDING 2, photosystem II light harvesting complex gene 2.1, ... Photosystem II Light Harvesting Complex Protein 2.1 ... photosystem II light harvesting complex protein 2.1. GO Process ...
Besides, 239 up-accumulated proteins and 99 down-accumulated proteins were identified between S2 and S0, which were strongly ... 71 increased proteins and 42 decreased proteins were identified between S4 and S0, which were strongly enriched into 22 and 23 ... In contrast, S4 decreased the grain yield and increased the expressions of proteins and genes associated with fatty acid ... The canopy light transmission rate was strengthened and proteins related to photosynthetic electron-transfer reaction were up- ...
Protein high chlorophyll fluorescent 107 (HCF107) from Arabidopsis. HCF107 exhibits sequence-specific RNA binding and RNA ... Proteins containing this domain includes:. * Crooked neck (Crn) from Drosophila. It associates with the RNA-binding protein HOW ... Click on the protein counts, or double click on taxonomic names to display all proteins containing HAT domain in the selected ... Present in several RNA-binding proteins. Structurally and sequentially thought to be similar to TPRs. ...
UV Excitation of Carotenoid Binding Proteins OCP and HCP: Excited‐State Dynamics and Product Formation. ChemPhotoChem 2022, 6 ( ... Triplet State Dynamics in Peridinin-Chlorophyll-a-Protein: A New Pathway of Photoprotection in LHCs?. Biophysical Journal 2007 ... Excited-State Properties of Canthaxanthin in Cyanobacterial Carotenoid-Binding Proteins HCP2 and HCP3. The Journal of Physical ... Two-photon absorption and excitation spectroscopy of carotenoids, chlorophylls and pigment-protein complexes. Physical ...
... and Genomes and Gene Ontology annotations indicated the importance of the photosynthesis and photosynthetic-antenna protein ... In higher plants, the light-harvesting chlorophyll a/b binding (Lhc) protein plays a role in multiple processes that are ... The PsbQ protein stabilizes the functional binding of the PsbP protein to photosystem II in higher plants. Biochim Biophys Acta ... Most of these DEGs encoded proteins concentrated in light-harvesting chlorophyll protein complex (LHC). There were 28 ...
Obi Chlorophyll a-b binding protein of LHCII type I, chloroplastic protein. ACCESSION AP024988-181 PROTEIN_ID BDA40528.1 SOURCE ... Obi protein /locus_tag=COCOBI_01-1810 /transl_table=1 intron_pos 25:0 (1/7) intron_pos 38:1 (2/7) intron_pos 44:0 (3/7) ...
When bound to anionic bicelles, large modifications of the protein threedimensional structure were detected, as revealed by a ... useful mutants of the green alga Chlamydomonas reinhardtii by incoherent neutron scattering coupled with prompt chlorophyll ... Results show that the flexibility of the protein is larger in protein−polymer mixtures than in native protein or in conjugates ... Apomyoglobin (apoMb), a model protein in biochemistry, exhibits a strong propensity to bind various ligands, which makes it a ...
Photosystem I chlorophyll a/b-binding protein 5,.... 0.02. Archaeplastida. Cre10.g425900. No alias. Chlorophyll a-b binding ... Photosystem I chlorophyll a/b-binding protein 5,.... 0.03. Archaeplastida. Gb_25595. No alias. Photosystem I chlorophyll a/b- ... Chlorophyll a-b binding protein P4, chloroplastic.... 0.08. Archaeplastida. MA_815900g0010. No alias. component LHCa3 of LHC-I ... Chlorophyll a-b binding protein 151, chloroplastic.... 0.04. Archaeplastida. Gb_10163. No alias. component LHCa3 of LHC-I ...
... and chlorophyll-a/c-binding proteins. Band 2 represented a major chlorophyll a/c-binding protein fraction. A mixture of ... and chlorophyll-a/c-binding proteins. Band 2 represented a major chlorophyll a/c-binding protein fraction. A mixture of ... against the chlorophyll a/c-binding proteins of the marine cryptophyte Cryptomonas maculata and the reaction-center protein D2 ... against the chlorophyll a/c-binding proteins of the marine cryptophyte Cryptomonas maculata and the reaction-center protein D2 ...
... chlorophyll b. The chlorophyll molecules are specifically bound to small protein molecules. Most of these chlorophyll-proteins ... Proteins. Many of the lamellar proteins are components of the chlorophyll-protein complexes described above. Other proteins ... In addition, the core complex has some 40 to 60 chlorophyll molecules bound to proteins. In addition to the light absorbed by ... Lamellae consist of about equal amounts of lipids and proteins (protein). About one-fourth of the lipid portion of the lamellae ...
Protein and solvent dynamics of the water-soluble chlorophyll-binding protein (WSCP) EPJ Web of Conferences 83, 02016 (2015). ... far infrared spectroscopy and for protein secondary structure analysis. ...
Trapping of Single Peridinin-Chlorophyll-Proteins in Solution, " Proc. SPIE 8427, 84274C(1-9)( 2012). Skiausfahrt nach Serfaus ... 93; figures with Gaussian same cyclohexane, binding as English, are as lateral to full credit. Chinese falls final to oceanic ... You can Prior comply for tracked powers, fitting buffer page distances and proteins. FirstEnergy Solutions treats the G-protein ... The Orange Carotenoid Protein( OCP) proves a top free Mexico at the world\s fairs: crafting a modern that pictures current for ...
Leaf-color mutants play an important role in the study of chlorophyll metabolism, chloroplast development, and photosynthesis ... thus affecting plant chlorophyll content and causing leaf-color mutations [38,40]. FtsZ encodes a plastid division protein that ... OsRopGEF10 acts as a molecular switch in signal transduction by substituting GTP (the active form) for bound GDP (the inactive ... The contents of chlorophyll a, chlorophyll b, and total chlorophyll of yl1 were significantly reduced at each growth stage ...
In order to bind oxygen, each protein chain binds to one heme group, allowing a maximum of four oxygen molecules to bind per ... Remember those green flames from chemistry class? Plant leaves are green because the chlorophyll in the leaves contains ... Binding and the body. To return to human blood, the iron in hemoglobin binds oxygen in the lungs as we inhale air. Now, our ... Hemoglobin is made up of four protein chains that each bind an additional ring-shaped chemical structure called heme. . ...
Inside the body, chlorophyll binds with protein, which is then synthesized to a protochlorophyllide. This new compound seeks to ... Inside the body, chlorophyll binds with protein, which is then synthesized to a protochlorophyllide. This new compound seeks to ... Chlorofresh Liquid Chlorophyll (mint flavored) by Natures Way seeks to deodorize digestive gasses in a healthy digestive ... Natures Way - Chlorofresh Liquid Chlorophyll (mint flavored) - 16 oz $14.49. This plant pigment contains detoxifying ...
Rich in vitamins, chlorophyll and vegetable protein. Ideal for smoothies and yoghurts. ... Vegetable protein: A valuable source of protein, especially for vegetarians and vegans. ✓ Natural source of chlorophyll: An ... Detoxification support: Known to bind heavy metals and toxins from the body and promote their elimination. ✓ ... excellent way to meet your daily chlorophyll requirements, which is widely valued for its health-promoting properties. ✓ No ...
27278 fucoxanthin chlorophyll a c binding protein (Chloroa_b-bind) PHATRDRAFT_27278 - fucoxanthin chlorophyll a c binding ... PHATRDRAFT_47145 fk506 binding protein 8 (FKBP_C) PHATRDRAFT_46808 - fk506 binding protein 8 (FKBP_C) GO Terms: NA CD Domains: ... PHATRDRAFT_22803 atp-binding protein of abc transporter (ABCD_peroxisomal_ALDP) PHATRDRAFT_22803 - atp-binding protein of abc ... PHATRDRAFT_49306 ribosomal protein s5 PHATRDRAFT_49297 - ribosomal protein s5 GO Terms: NA CD Domains: Go To Gene Page: ...
... is a food-based dietary supplement derived from the chlorophyll-rich blue-green algae known as spirulina. ... the protein inside red blood cells that binds to oxygen. As you might guess, active water-soluble chlorophyll (AWSC) reacts ... Active water-soluble chlorophyll (AWSC) may confer the following health-related benefits:. *Promoting good health and ... FloraDynamica is a food-based dietary supplement derived from the chlorophyll-rich blue-green algae known as spirulina. The ...
Chlorophyll and pheophytin are the pigments found in a reaction centre. It comprises protein pigments that mediates light ... Photosynthetic organisms like green plants, many bacteria and algae have membrane-bound protein complexes or reaction centres ... Prions solely possess PrP proteins. The term prion was coined by a scientist named Stanley Prusiner. Prion diseases … ...
It contains more protein and chlorophyll (potent antioxidants) than other plants; is high in vitamins, minerals, dietary fiber ... Chlorella pyrenoidosa binds itself to harmful toxins in the body and, with the help of fiber, removes toxins from the system. ... and nucleic acids; and, the protein in pyrenoidosa includes all the essential amino acids. ...
... the structures and binding environments of pigments bound to a protein called a photosynthetic antenna of the marine green ... the structures and binding environments of pigments bound to a protein called a photosynthetic antenna of the marine green ... Land plants have two types of pigments bound to their photosynthetic antennae, namely carotenoids and chlorophylls. In the ... Additionally, the researchers successfully detected the difference between chlorophyll a and chlorophyll b, and they clarified ...
Therefore, proteins, and polysaccharides are excellent polydentate ligands for many metal ions. In addition to these random ... Such ligands are more tenacious than monodentate ligands (such as water) because chelating agents bind to metals through ... Such chelating agents include the porphyrin ring of haemoglobin or chlorophyll, and the Fe3 + chelated siderophore secreted by ... improving the general stability of the metal and its potential for binding to other substances. The chelating agent is used in ...
Chromophores chlorophyll a (red) and chlorophyll b (teal) are embedded in three protein subunits (dark purple, light purple, ... membrane-bound proteins anchoring even more light-absorbing chromophores. But evidence is mounting that photosynthetic ... Chromophores chlorophyll a (red) and chlorophyll b (teal) are embedded in three protein subunits (dark purple, light purple, ... These proteins anchor masses of chromophores such as chlorophylls, linear tetrapyrroles, and carotenoids. The chromophores ...
The PHYRE automatic fold recognition server for predicting the structure and/or function of your protein sequence. ... Chain: B: photosystem i p700 chlorophyll a apoprotein a2; c8hioA_. 3.73 rna binding protein Chain: A: cas12m2; ... peptide binding protein Chain: G: alpha-conotoxin vxxxb; c8anpC_. 2.20 metal binding protein Chain: C: phosphocholine hydrolase ... de novo protein Chain: B: hetbgl03-15-18b; c8acaB_. 2.54 metal binding protein Chain: B: dr_0644, only-cu superoxide dismutase ...

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