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What is the structure of Photosystem 1 and 2?

What is the structure of Photosystem 1 and 2?

Two large membrane protein complexes, photosystems I and II (abbreviated as PS I and PS II, respectively) are embedded in this membrane. They catalyze the initial step of photosynthesis, the light induced charge separation across the photosynthetic membrane.

What is the structure of a photosystem?

Each photosystem has two parts: a reaction center, where the photochemistry occurs, and an antenna complex, which surrounds the reaction center. The antenna complex contains hundreds of chlorophyll molecules which funnel the excitation energy to the center of the photosystem.

What happens in the photosystem 1?

Photosystem I receives electrons from plastocyanin or cytochrome c6 on the lumenal side of the thylakoid membrane and uses light energy to transfer them across the membrane to ferredoxin on the stromal side. It can also function in a cyclic electron transport pathway.

What is the function of photosystem II and photosystem I?

During this process, the water-splitting and oxygen-evolving reaction is catalyzed by photosystem II (PSII), while photosystem I (PSI) generates the reducing power for the reduction of NADP+ to NADPH.

Where is photosystem 1 and 2 located?

Two types of photosystems, photosystem I (PSI) and photosystem II (PSII), are found in the thylakoid membrane inside the chloroplast. Each photosystem consists of multiple antenna proteins that contain a mixture of 300–400 chlorophyll a and b molecules, as well as other pigments like carotenoids.

What is ps1 and ps2 in photosynthesis?

Photosystem I (PS I) and photosystem II (PS II) are two multi-subunit membrane-protein complexes involved in oxygenic photosynthesis. The main difference between photosystem 1 and 2 is that PS I absorbs longer wavelengths of light (>680 nm) whereas PS II absorbs shorter wavelengths of light (<680 nm).

Where is photosystem 1 found?

thylakoid membranes
Physically, photosystems are found in the thylakoid membranes. There are two kinds of photosystems: photosystem I (PSI) and photosystem II (PSII) (Fig. 3.3). PSII acts first during the light transformation process in photosynthesis, but it was named PSII because it was discovered second.

Where are the photosystems 1 and 2 found?

thylakoid membrane
Two types of photosystems, photosystem I (PSI) and photosystem II (PSII), are found in the thylakoid membrane inside the chloroplast. Each photosystem consists of multiple antenna proteins that contain a mixture of 300–400 chlorophyll a and b molecules, as well as other pigments like carotenoids.

Why ps1 is also called P700?

Etymology. Its name is derived from the word “pigment” (P) and the presence of a major bleaching band centered around 695-700 nm in the flash-induced absorbance difference spectra of P700/ P700+•.

What is the role of photosystems in photosynthesis?

Photosystems are the functional units for photosynthesis, defined by a particular pigment organization and association patterns, whose work is the absorption and transfer of light energy, which implies transfer of electrons. Physically, photosystems are found in the thylakoid membranes.

How are photosystem 1 and 2 connected?

The connecting electron carriers are oxidized by photosystem I (PS I) and reduced by photosystem II (PS II). The control counteracts the imbalance in electron transport that causes it: oxidized plastoquinone induces PS II and represses PS I; reduced plastoquinone induces PS I and represses PS II.

What is photosystem in photosynthesis?