What structures are described as molecular arrays of chlorophyll and proteins that capture light energy?

Photosystems are indeed the structures that are molecular arrays of chlorophyll and proteins designed to capture light energy during the process of photosynthesis. Each photosystem consists of a core of chlorophyll molecules and various accessory pigments, along with proteins that help organize and stabilize the complex. These components work together to absorb light energy and convert it into chemical energy through a series of electron transport reactions.

In this context, it is important to note that while thylakoids are membrane-bound compartments within chloroplasts where the light reactions occur, they serve as the physical space for photosystems to function rather than being the capturing units themselves. The stroma is the fluid-filled area surrounding the thylakoids in the chloroplast, where the light-independent reactions (Calvin cycle) occur, but it does not play a role in capturing light energy directly. Plastids are a broader category of organelles within plant cells that can store substances and contribute to photosynthesis but do not specifically refer to the structures responsible for capturing light energy. Therefore, photosystems are specifically tailored for this function in photosynthesis, highlighting their importance in energy transformation in plants.