Question

Which compounds link the light reactions with the Calvin cycle reactions?

A) ATP and NADPH
B) H⁺ and ATP
C) G3P and ATP
D) H⁺ and G3P
E) G3P and NADPH

Answer 1

ATP and NADPH are the compounds that link the light reactions with the Calvin cycle in photosynthesis. These molecules supply energy and reducing power for synthesizing glucose from carbon dioxide in the Calvin cycle and then cycle back to the light-dependent reactions to be recharged.

Step-by-step explanation:

The compounds that link the light reactions with the Calvin cycle reactions are ATP and NADPH. These energy carriers are crucial as they provide the chemical energy and reducing power needed by the Calvin cycle to convert carbon dioxide into glucose.

During the light-dependent reactions, sunlight energy is converted into chemical energy in the form of ATP and NADPH. These molecules then enter the light-independent reactions, commonly known as the Calvin cycle, where they are used to convert the three-carbon compound 3-PGA into glyceraldehyde 3-phosphate (G3P). This reaction is a reduction reaction because it involves the gain of electrons. The ATP molecule releases energy by losing a phosphate group and becomes ADP, while NADPH loses a hydrogen atom and becomes NADP+. After releasing their stored energy, both ADP and NADP+ return to the light-dependent reactions to be re-energized.