Question

The energy required to run the Calvin cycle reactions of photosynthesis comes from which two substances produced during the light-dependent reactions?

a. ATP and NADPHb. ADP and PO4c. H+ and O2d. O2 and CO2e. H2O and CO2

Answer 1

a. ATP and NADPH

Step-by-step explanation:

Light-dependent reactions of photosynthesis include splitting of water in the presence of sunlight and release of electrons. The electrons move from the reaction center of the PS-II via electron carriers to the PS-I. From the reaction center of PS-I, the electrons finally reach NADP reductase and reduce NADP into NADPH.

During this electron transfer via electron carriers, a proton concentration gradient is generated across the thylakoid membrane. The energy of this gradient is used to drive ATP synthesis. ATP and NADPH formed during the light-dependent phase of photosynthesis are then used during the reactions of the Calvin cycle.