Protein complexes involved in photosynthesis include structural and functional components called photosystems. Together, they perform the basic photochemistry of photosynthesis, which entails the transfer of energy and electrons as well as the absorption of light. Plants, algae, and cyanobacteria all have thylakoid membranes that contain photosystems.
The two multi-protein complexes known as photosystem I and photosystem II contain the pigments required to collect photons and utilize light energy to catalyze the fundamental photosynthetic endergonic processes that result in high-energy molecules.
The two main parts of the photosystem are the antennae and the reaction center.
Antennae: It is formed of hundreds of pigment molecules that capture the photons and transfer the light energy harvested to the reaction center.
Reaction Centre: It captures the energy of the photons and turns it into a usable form.
A reaction center, where the photochemistry takes place, and an antenna complex, which encircles the reaction center, are the two components of each photosystem. Numerous chlorophyll molecules in the antenna complex direct the excitation energy toward the photosystem's core.