Final answer:
The structure not a component of a photosystem is the stroma, which is the fluid space surrounding thylakoids in chloroplasts and is involved in the Calvin cycle, not the light-capturing reactions of photosynthesis.
Step-by-step explanation:
The photosystem is a crucial component in the process of photosynthesis, allowing plants and certain bacteria to convert light energy into chemical energy. A photosystem typically comprises several key components, including antenna pigments (such as chlorophyll and carotenoids), a reaction center, and a primary electron acceptor. The antenna pigments are responsible for capturing photons of light and funneling that energy to the reaction center. Once the energy reaches the reaction center, it excites an electron which is then transferred to the primary electron acceptor. This process initiates a series of reactions that ultimately convert light energy into chemical energy stored in ATP and NADPH.
The correct answer to the question, "Which of the following structures is not a component of a photosystem?" is 'c) Stroma.' The stroma is the fluid-filled space surrounding the thylakoids in chloroplasts, but it is not a direct component of the photosystem itself. Instead, the stroma is involved in the Calvin cycle and other reactions in the chloroplast. In contrast, ATP synthase, although not listed as a correct answer here, is also not a part of the photosystem but is associated with the thylakoid membrane and involved in the synthesis of ATP through chemiosmosis.