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  • redox
  • This green alga is metabolically flexible and can sustain energy generation and maintain cellular redox balance under a variety of different environmental conditions. (frontiersin.org)
  • Absorption
  • Absorption of visible light by a chromophore molecule is known to induce transfer of an electron from the main orbital (S0) to one of the singlet (S1 * , S2 * …) or triplet (T) excited orbitals (Fig. 2.2). (slideshare.net)
  • This technology allows for the application of single or multiple turnover subsaturating excitation pulses at microsecond intervals to induce fluorescence transients, allowing measurements of the photochemical conversion efficiency in PSII (Fv/Fm), the functional absorption cross section of PSII (σPSII) and the energy transfer between PSII units (p). (carnegiescience.edu)
  • protein
  • Effective regulatory protein expression related to energy, stress defense, and carbohydrate metabolism play important roles in the salt-tolerance of H. glomeratus suspension cell cultures. (frontiersin.org)
  • Acclimation instead is a more complex long term process that acts directly modeling the composition of the photosynthetic apparatus in response to different light intensity, for example through modifications in protein composition. (unipd.it)
  • Processes
  • For instance, when using an ultrafast laser one can generate a 2 9 10-14 s long flash of light so as to study kinetics and mechanisms of the primary processes of light energy storage. (slideshare.net)
  • It binds chlorophyll and helps catalyze the primary light-induced photochemical processes of PSII. (string-db.org)
  • A significant portion of biological processes are involved with providing vital energy sources such as ATP, and controlling the flow of energy through living systems. (pubmedcentralcanada.ca)
  • solar
  • It is the only major natural solar energy storage mechanism on Earth. (frontiersin.org)
  • In a previous study, ethanol synthesis was obtained by introducing pyruvate decarboxylase and alcohol dehydrogenase genes from Z. mobilis into a unicellular cyanobacterium, Synechococcus [ 14 ], indicating the feasibility of constructing an integrated system for converting solar energy and inorganic carbon source into biofuel directly. (biomedcentral.com)
  • Among renewable and exploitable energy resources, nuclear fusion energy or solar energy are by far the largest. (royalsocietypublishing.org)
  • If solar energy is to be a major primary energy source, then it must be stored and despatched on demand to the end user. (royalsocietypublishing.org)
  • Therefore, the scientific challenge is to construct an 'artificial leaf' able to efficiently capture and convert solar energy and then store it in the form of chemical bonds of a high-energy density fuel such as hydrogen while at the same time producing oxygen from water. (royalsocietypublishing.org)
  • renewable
  • Additionally, when Chlamydomonas ferments polysaccharides, it has the ability to eliminate part of the reductant (to sustain glycolysis) through the production of H 2 , a molecule that can be developed as a source of renewable energy. (frontiersin.org)
  • Accordingly, enormous efforts are directed to transition from fossil fuels to nonpolluting and renewable energy sources. (mdpi.com)
  • The limited availability of global fossil fuel reserves and concerns about global climate change from GHG emissions prompted notable interest in the investigation and development of eco-friendly, renewable energy alternatives to fulfill the growing energy demands [ 3 ]. (mdpi.com)
  • biomass
  • When we burn fuels (fossil, biomass and other biofuels) to release energy, we are simply combining the 'hydrogen' stored in these organic molecules with atmospheric oxygen to form water, so completing a cycle started millions of years ago. (royalsocietypublishing.org)
  • chlorophyll
  • 1. Chapter 2 Chlorophyll-Based Generators of Proton Potential Generators of D'lHþ play a leading role in the conversion of external energy sources into forms that can be used by living cells. (slideshare.net)
  • However, because excess light is harmful, plants engage several protective mechanisms, including non-photochemical quenching (NPQ) of chlorophyll (Chl) fluorescence. (biomedcentral.com)
  • chloroplasts
  • Chloroplasts have already evolved significant energy flexibility mechanisms, as discussed below, but these are activated under specific environmental and metabolic challenges. (plantphysiol.org)
  • This view, however, has to be abandoned in the light of a series of experiments showing robust transcriptional regulation of genes in mature plant chloroplasts [ 19 - 21 ]. (royalsocietypublishing.org)
  • alternatives
  • Ethanol and butanol are clean energy sources with good chemical and physical properties as alternatives to gasoline. (biomedcentral.com)
  • 1 Biosciences and Biotechnologies Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS and Aix-Marseille University, UMR 7265 LB3M, CEA Cadarache, F-13108, Saint-Paul-lez-Durance, France. (sciencemag.org)
  • driven
  • First of all, we consider them to have been the primordial systems for proton potential generation driven by external energy sources during the evolution of life. (slideshare.net)
  • PSII
  • Prior to performing this fluorescence measurement, algal samples are incubated for 10 min in the dark and then exposed to 10 min of far-red light (activating PSI photochemistry) in order to make sure that PSII (and the PQ pool) is fully oxidized and that the cells are in state 1 prior to the measurement. (carnegiescience.edu)
  • qP measures photochemical quenching, providing information about the proportion of PSII reaction centers that are available for photochemistry after exposure of the cells to different light intensities (they are grown at one light intensity and then exposed to various intensities for 5-10 min). (carnegiescience.edu)
  • If the qP values in mutant cells are comparable to those of wild-type cells, it is likely that the mutants are able to acclimate to the various light conditions used for growth and that the extent to which PSII traps remain opened is optimal. (carnegiescience.edu)
  • ΦPSII is related to qP and indicates the photochemical yield of PSII at different light intensities. (carnegiescience.edu)
  • In studies presented here, under fluctuating high light, growth of young seedlings lacking PsbS is retarded, and PSII in detached leaves of the mutants is more sensitive to photoinhibitory illumination compared with the wild type. (biomedcentral.com)
  • organisms
  • Sunlight is the ultimate source of energy for most organisms on Earth. (psu.edu)
  • The energy needed by all living organisms is derived ultimately from the sun. (schoolbag.info)
  • Hence, to use the energy of the sun, living organisms require a mechanism for capturing individual photons and storing the energy they contain. (schoolbag.info)
  • Sunlight
  • However, most energy contained in sunlight is dissipated as heat, which is insufficient to break and form all but the weakest chemical bonds. (schoolbag.info)
  • On the other hand, 1 h of sunlight falling on our planet is equivalent to all the energy consumed by humans in an entire year. (royalsocietypublishing.org)
  • intensities
  • Cells grown in high light also show increased photosynthetic electron transport, paralleled by an increased contribution of cyclic electron transport around Photosystem I. Even when exposed to extreme light intensities, Nannochloropsis cells do not activate photo-protection responses, such as NPQ and the xanthophyll cycle in a constitutive way. (unipd.it)
  • photosynthetic apparatus
  • The regulation of the photosynthetic apparatus in this interesting microalgae has been deeply discussed in Section B. Our study focused firstly on the acclimation response in Nannochloropsis gaditana subjected to prolonged exposition to low and high light. (unipd.it)
  • The influence on NPQ seems to be related mostly on de novo synthesis of zeaxanthin while the molecules already present in the photosynthetic apparatus are involved in a transient NPQ active only in the first minute after the dark-light transition. (unipd.it)
  • NADPH
  • The product of Photosystem I is NADPH, a molecule with about the same standard free energy of combustion as hydrogen. (psu.edu)
  • For example, adding a C 4 pathway to a C 3 plant would increase the ATP/NADPH demand, whereas increasing the storage of energy in saturated fats or oils would decrease it. (plantphysiol.org)
  • Attempts to infer ATP/NADPH production and consumption at low irradiance require assumptions about how light is distributed between the two photosystems, how many protons are translocated to the lumen per electron, and how many protons are required to form ATP. (plantphysiol.org)
  • fossil fuels
  • The world's dependence on fossil fuels for energy is fraught with a variety of environmental, social and political problems. (psu.edu)
  • These fossil fuels are the products of photosynthetic activity millions of years ago and provide us with most of the energy needed to power our technologies, heat our homes and produce the wide range of chemicals and materials that support everyday life. (royalsocietypublishing.org)
  • molecules
  • The ligand-only view of the crystal structure reveals a picture that should be somewhat familar now: a host of antennae molecules forming a light-harvesting complex. (csbsju.edu)
  • Interestingly zeaxanthin molecules are found to be constitutively present in this microalga, even in conditions of very low light in which the xanthophyll cycle is not yet induced. (unipd.it)
  • Similarly, energy is also released from the organic molecules which constitute our food, when they are metabolized within our bodies by the process of respiration. (royalsocietypublishing.org)
  • carbon dioxide
  • However, the cumulative nature of carbon dioxide (CO 2 ) emissions demands that stabilizing the atmospheric CO 2 levels to just twice their pre-anthropogenic values by mid-century will be extremely challenging, requiring invention, development and deployment of schemes for carbon-neutral energy production on a scale commensurate with, or larger than, the entire present-day energy supply from all sources combined. (royalsocietypublishing.org)