Question

which process splits water molecules using light energy to replace electrons? a calvin cycle b krebs cycle c photolysis d cellular respiration

Explanation:

• Calvin cycle: It is the light - independent stage of photosynthesis where carbon fixation occurs. It does not split water molecules using light energy.
• Krebs cycle: It is a part of cellular respiration (aerobic) that occurs in the mitochondria. It is involved in the breakdown of acetyl - CoA and not in splitting water molecules with light energy.
• Photolysis: In the light - dependent reactions of photosynthesis, light energy is used to split water molecules (\(H_2O\)). The electrons from water are used to replace the electrons lost from the reaction center of photosystem II. The general equation for photolysis is \(2H_2O

ightarrow4H^{+}+O_2 + 4e^{-}\).

• Cellular respiration: It is the process by which cells break down organic molecules (such as glucose) to release energy. It does not use light energy to split water molecules.

Answer:

C. photolysis