1. Complexes of proteins and pigments in the thylakoid membranes of chloroplasts that capture light energy and convert it into chemical energy during photosynthesis.
Usage: plural form of photosystem; technical/scientific term; commonly referred to as Photosystem I (PSI) and Photosystem II (PSII) in plants

Examples

• Photosystems are essential structures for converting sunlight into usable energy in plant cells.
• The two main photosystems work together to drive the light-dependent reactions of photosynthesis.
• Photosystem II absorbs light energy and splits water molecules to release oxygen.
• Researchers study photosystems to understand how plants efficiently capture solar energy.
• Damage to photosystems can reduce a plant's ability to photosynthesize effectively.