Photosystem

Together they carry out the primary photochemistry of photosynthesis: the absorption of light and the transfer of energy and electrons.

The antenna complex contains hundreds of chlorophyll molecules which funnel the excitation energy to the center of the photosystem.

[2] The main function of PSII is to efficiently split water into oxygen molecules and protons.

PSII will provide a steady stream of electrons to PSI, which will boost these in energy and transfer them to NADP+ and H+ to make NADPH.

At the heart of a photosystem lies the reaction center, which is an enzyme that uses light to reduce and oxidize molecules (give off and take up electrons).

The pigments which absorb light at the highest energy level are found furthest from the reaction center.

The reaction center will drive photosynthesis by taking light and turning it into chemical energy[3] that can then be used by the chloroplast.

Both reaction center types are present in chloroplasts and cyanobacteria, and work together to form a unique photosynthetic chain able to extract electrons from water, creating oxygen as a byproduct.

A reaction center comprises several (about 25-30)[6] protein subunits, which provide a scaffold for a series of cofactors.

In the reaction center of PSII of plants and cyanobacteria, the light energy is used to split water into oxygen, protons, and electrons.

At the core of photosystem II is P680, a special chlorophyll to which incoming excitation energy from the antenna complex is funneled.

This reducing (hydrogenation) agent is transported to the Calvin cycle to react with glycerate 3-phosphate, along with ATP to form glyceraldehyde 3-phosphate, the basic building block from which plants can make a variety of substances.