Question

What is the name of cycle, which generates energy and splits water into hydrogen and oxygen?

• A. Glycolysis
• B. Photophosphorylation
• C. Citric acid cycle
• D. Electron transport cycle

Answer 1

Answer: (B)

Photophosphorylation

Photophosphorylation refers to the use of light energy to ultimately provide the energy to convert ADP to ATP, thus replenishing the universal energy currency in living things. The light energy entering the plant splits water into hydrogen and oxygen.

H${}_2$O + light energy -----> O ${}_2$ + 2H${}^{-}$ + 2 electrons

These electrons travel through a membrane bound electron transport chain much like the electrons in oxidative phosphorylation, using their energy to pump protons through the membrane. The proton gradient thus established can be used to synthesize ATP.