Final answer:
The structures and molecules involved in the light reactions of photosynthesis include photosystems 1 and 2, chlorophyll b, carotenoids, thylakoid membranes, and the ATP synthase enzyme.
Step-by-step explanation:
The structures and molecules involved in the light reactions of photosynthesis include photosystems 1 and 2, chlorophyll b, carotenoids, thylakoid membranes, and the ATP synthase enzyme. Photosystems 1 and 2 are clusters of pigments that capture light energy. Chlorophyll b and carotenoids are accessory pigments that assist in light absorption. Thylakoid membranes contain the photosystems and provide a site for the light reactions to occur. The ATP synthase enzyme is responsible for the synthesis of ATP.