2. What color/s of light does chlorophyll absorb? What color does it reflect? 3. What composes a photosystem? 4. In what part of the photosystem does the first step of light reaction take place? 5. Differentiate the two types of photosystem.
Green light. As shown in detail in the absorption spectra, chlorophyll absorbs light in the red (long wavelength) and the blue (short wavelength) regions of the visible light spectrum. Green light is not absorbed but reflected, making the plant appear green. Chlorophyll is found in the chloroplasts of plants.
A photosystem consists of a light-harvesting complex and a reaction center. Pigments in the light-harvesting complex pass light energy to two special chlorophyll a molecules in the reaction center. The light excites an electron from the chlorophyll a pair, which passes to the primary electron acceptor.
thylakoid membrane. The light reactions occur in several steps, all of which take place in the thylakoid membrane, as shown in Figure below. Step 1: Units of sunlight, called photons, strike a molecule of chlorophyll in photosystem II of the thylakoid membrane.
Photosystems II and I have different chlorophylls. PS II has P680 and PS I has P700. Photosystem II comes before Photosystem I.
