Second protein complex in photosynthetic light reactions
"PS I" redirects here. For other uses, see PSI (disambiguation). For PS1, see PlayStation 1.
Light-dependent reactions of photosynthesis at the thylakoid membrane
Photosystem I
Plant photosystem I with LHC I
Identifiers
EC no.
1.97.1.12
Databases
IntEnz
IntEnz view
BRENDA
BRENDA entry
ExPASy
NiceZyme view
KEGG
KEGG entry
MetaCyc
metabolic pathway
PRIAM
profile
PDB structures
RCSB PDB PDBe PDBsum
Search
PMC
articles
PubMed
articles
NCBI
proteins
Location of the psa genes in the chloroplast genome of Arabidopsis thaliana. The 21 protein-coding genes involved in photosynthesis are displayed as green boxes.
Photosystem I (PSI, or plastocyanin–ferredoxin oxidoreductase) is one of two photosystems in the photosynthetic light reactions of algae, plants, and cyanobacteria. Photosystem I [1] is an integral membrane protein complex that uses light energy to catalyze the transfer of electrons across the thylakoid membrane from plastocyanin to ferredoxin. Ultimately, the electrons that are transferred by Photosystem I are used to produce the moderate-energy hydrogen carrier NADPH.[2] The photon energy absorbed by Photosystem I also produces a proton-motive force that is used to generate ATP. PSI is composed of more than 110 cofactors, significantly more than Photosystem II.[3]
^Golbeck JH (1987). "Structure, function and organization of the Photosystem I reaction center complex". Biochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics. 895 (3): 167–204. doi:10.1016/s0304-4173(87)80002-2. PMID 3333014.
^Yamori W, Shikanai T (April 2016). "Physiological Functions of Cyclic Electron Transport Around Photosystem I in Sustaining Photosynthesis and Plant Growth". Annual Review of Plant Biology. 67: 81–106. doi:10.1146/annurev-arplant-043015-112002. PMID 26927905.
^Nelson N, Yocum CF (2006). "Structure and function of photosystems I and II". Annual Review of Plant Biology. 57: 521–65. doi:10.1146/annurev.arplant.57.032905.105350. PMID 16669773.
PhotosystemI (PSI, or plastocyanin–ferredoxin oxidoreductase) is one of two photosystems in the photosynthetic light reactions of algae, plants, and...
Photosystems are functional and structural units of protein complexes involved in photosynthesis. Together they carry out the primary photochemistry of...
Photosystem II (or water-plastoquinone oxidoreductase) is the first protein complex in the light-dependent reactions of oxygenic photosynthesis. It is...
membrane: PhotosystemsI and II Cytochrome b6f complex ATP synthase Photosystem II is located mostly in the grana thylakoids, whereas photosystemI and ATP...
that are part of larger supercomplexes known as P700 in PhotosystemI and P680 in Photosystem II. The structures of these supercomplexes are large, involving...
P700, or photosystemI primary donor, is a molecular dimer of chlorophyll a associated with the reaction-center of photosystemI in plants, algae, and...
P700, a pigment in a complex called photosystemI, flows in a cyclic pathway. The electron starts in photosystemI, passes from the primary electron acceptor...
the O2 in Earth's atmosphere. PhotosystemI typically works in series with Photosystem II; thus the P700+ of PhotosystemI is usually reduced as it accepts...
(P700) of photosystemI are replaced by transfer from plastocyanin, whose electrons come from electron transport through photosystem II. Photosystem II, as...
quantasome is thought to represent the site of photosystemI, the larger to represent the site of photosystem II.[clarification needed] Light-dependent reactions...
shade-adapted chloroplasts, which have an increased ratio of photosystem II to photosystemI, there is a higher ratio of chlorophyll b to chlorophyll a. This is...
during photosynthesis, forming part of the electron transport chain of photosystemI. The best-known function of vitamin K in animals is as a cofactor in...
is one step along the chain that transfers electrons from Photosystem II to PhotosystemI, and at the same time pumps protons into the thylakoid space...
P680, or photosystem II primary donor, is the reaction-center chlorophyll a molecular dimer associated with photosystem II in plants, algae, and cyanobacteria...
antennae that transmit the energy of harvested photons to photosystem II and photosystemI in cyanobacteria and in the chloroplasts of red algae and glaucophytes...
molecules absorb red-light photons at a wavelength of 700 nm in the photosystemI, corresponding to an energy of each photon of ≈ 2 eV ≈ 3×10−19 J ≈ 75 kBT...
photosystem II. The electrons are used to reduce carbon dioxide, which eventually becomes incorporated into sugars. Photo-excitation o photosystemI initiates...
solar cell is a solar cell made using a combination of organic matter (photosystemI) and inorganic matter. Biohybrid solar cells have been made by a team...
its two photosystems. Non-oxygenic bacteria, on the other hand, have an RC resembling either the PhotosystemI centre (Type I) or the Photosystem II centre...
molecules are located in both photosystem II and photosystemI. They are known as P680 for Photosystem II and P700 for PhotosystemI. P680 and P700 are the primary...
herbicides are cell membrane disruptors that are either "PPO inhibitors" or "PhotosystemI inhibitors." Plant cells have chloroplasts, which contain the protoporphyrinogen...
G protein coupled receptors (e.g., Beta-adrenergic receptor) Seipin PhotosystemI Membrane protein Transmembrane protein Peripheral membrane protein Annular...
plants, it accepts electrons from photosystemI (more specifically ferredoxin, which is presented with electrons from PS I) and transfers them to molecular...
(diuron) are photosystem II inhibitors. Other members of this class are chlorbromuron, pyrazon, isoproturon, bromacil, and terbacil. PhotosystemI inhibitors...
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