These include chlorophyll and other light capturing pigments, cytochromes, and other electron carriers, and ATP, which is the energy transfer molecule involved in almost all the energy transactions of the cell. The carotenoids are red, orange, or yellow, fat-soluble pigments found in all chloroplasts. A single leaf cell may contain 40-50 chloroplasts. Chloroplasts seem capable of independent movement within the cytoplasm and orient their surfaces in relation to the light. All of the chlorophyll and the carotenoids are found in association with the lamella and grana.
Light energy is trapped in the grana.
The reactions in which sugar is formed from carbon dioxide and water, using energy from the grana, takes place in the stroma. When light falls on an object, certain colors are absorbed and others are reflected. Similarly, chlorophyll is green because it absorbs blue and red strongly but not green. Green is reflected and this is what we see. Obviously, if chlorophyll is instrumental in capturing light energy, it must first absorb that energy.