Question

Which one of the following is not true about the light reactions of photosynthesis?

• A. Light energy provides energy for the photolysis of water through excitation of the reaction centre of PS-II
• B. The flow of electrons from water to NADP in noncyclic electron transport produces one ATP
• C. Reactions of the two photosystems are needed for the reduction of NADP
• D. P680 and P700 are the reaction centers of PS-I and PS-II, respectively
• E. NADPH is not produced in cyclic electron transport in light reaction

Answer 1

The correct option is D P680 and P700 are the reaction centers of PS-I and PS-II, respectively

Of the given statements, only the statement "P680 and P700 are the reaction centres of PS-I and PS-II, respectively" is incorrect.
In photosystem-I, the photo centre is a special chlorophyll-a molecule called P700, which is active in the red and far red region of the light spectra. Where as, in Photosystem-II, the photo centre is a chlorophyll-a molecule called P680.