Bacteriochlorophylls: Pyrrole containing pigments found in photosynthetic bacteria.Rhodobacter sphaeroides: Spherical phototrophic bacteria found in mud and stagnant water exposed to light.Pheophytins: Chlorophylls from which the magnesium has been removed by treatment with weak acid.Chloroflexus: A genus of green nonsulfur bacteria in the family Chloroflexaceae. They are photosynthetic, thermophilic, filamentous gliding bacteria found in hot springs.Photosynthetic Reaction Center Complex Proteins: 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.Light-Harvesting Protein Complexes: 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.Chlorobi: A phylum of anoxygenic, phototrophic bacteria including the family Chlorobiaceae. They occur in aquatic sediments, sulfur springs, and hot springs and utilize reduced sulfur compounds instead of oxygen.Bacterial Chromatophores: Organelles of phototrophic bacteria which contain photosynthetic pigments and which are formed from an invagination of the cytoplasmic membrane.Chlorophyll: Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.Photosynthesis: 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)Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Energy Transfer: 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.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.Photosystem I Protein Complex: 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.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Search Engine: Software used to locate data or information stored in machine-readable form locally or at a distance such as an INTERNET site.PubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Computer User Training: Process of teaching a person to interact and communicate with a computer.Medical Subject Headings: Controlled vocabulary thesaurus produced by the NATIONAL LIBRARY OF MEDICINE. It consists of sets of terms naming descriptors in a hierarchical structure that permits searching at various levels of specificity.Information Storage and Retrieval: Organized activities related to the storage, location, search, and retrieval of information.Review Literature as Topic: Published materials which provide an examination of recent or current literature. Review articles can cover a wide range of subject matter at various levels of completeness and comprehensiveness based on analyses of literature that may include research findings. The review may reflect the state of the art. It also includes reviews as a literary form.Rhodospirillaceae: A family of phototrophic bacteria, in the order Rhodospirillales, isolated from stagnant water and mud.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Rhodopseudomonas: A genus of gram-negative, rod-shaped, phototrophic bacteria found in aquatic environments. Internal photosynthetic membranes are present as lamellae underlying the cytoplasmic membrane.Phototrophic Processes: Processes by which phototrophic organisms use sunlight as their primary energy source. Contrasts with chemotrophic processes which do not depend on light and function in deriving energy from exogenous chemical sources. Photoautotrophy (or photolithotrophy) is the ability to use sunlight as energy to fix inorganic nutrients to be used for other organic requirements. Photoautotrophs include all GREEN PLANTS; GREEN ALGAE; CYANOBACTERIA; and green and PURPLE SULFUR BACTERIA. Photoheterotrophs or photoorganotrophs require a supply of organic nutrients for their organic requirements but use sunlight as their primary energy source; examples include certain PURPLE NONSULFUR BACTERIA. Depending on environmental conditions some organisms can switch between different nutritional modes (AUTOTROPHY; HETEROTROPHY; chemotrophy; or phototrophy) to utilize different sources to meet their nutrients and energy requirements.Carotenoids: 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.Ochromonas: A genus of GOLDEN-BROWN ALGAE in the family Ochromonadaceae, found mostly in freshwater. They bear two unequal FLAGELLA and are heterotrophic.Rhodospirillum: A genus of gram-negative, spiral bacteria that possesses internal photosynthetic membranes. Its organisms divide by binary fission, are motile by means of polar flagella, and are found in aquatic environments.Research: Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)Research Personnel: Those individuals engaged in research.Research Support as Topic: Financial support of research activities.Biomedical Research: Research that involves the application of the natural sciences, especially biology and physiology, to medicine.Evaluation StudiesEvaluation Studies as Topic: Studies determining the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies. For drugs and devices, CLINICAL TRIALS AS TOPIC; DRUG EVALUATION; and DRUG EVALUATION, PRECLINICAL are available.Research Design: A plan for collecting and utilizing data so that desired information can be obtained with sufficient precision or so that an hypothesis can be tested properly.WyomingHot Springs: Habitat of hot water naturally heated by underlying geologic processes. Surface hot springs have been used for BALNEOLOGY. Underwater hot springs are called HYDROTHERMAL VENTS.Chloroflexi: Phylum of green nonsulfur bacteria including the family Chloroflexaceae, among others.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Bacteria: One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.Molecular Chaperones: A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Secretory Vesicles: Vesicles derived from the GOLGI APPARATUS containing material to be released at the cell surface.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Guanosine Diphosphate: A guanine nucleotide containing two phosphate groups esterified to the sugar moiety.Dictionaries, MedicalDictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.Dictionaries, ChemicalTerminology as Topic: The terms, expressions, designations, or symbols used in a particular science, discipline, or specialized subject area.Phonetics: The science or study of speech sounds and their production, transmission, and reception, and their analysis, classification, and transcription. (Random House Unabridged Dictionary, 2d ed)DictionaryDictionaries, Pharmaceutic