Question

Oxygen released in photosynthesis is due to

• A. Photophosphorylation.
• B. Photolysis of water.
• C. Photorespiration.
• D. Photons.

Answer 1

The correct option is B Photolysis of water.

Photosynthesis is a process which occurs in two stages. The first is the light dependent reaction where the captured energy of light is used to make the ATP and NADPH. The second stage is where the reactions independent of light use these products to capture and reduce carbon dioxide. Photolysis is part of the light dependent reaction of the photosynthesis process.

Photosynthesis photolysis can be represented as H${}_2$A + 2 photons --> 2 e${}^{-}$ + 2H${}^{+}$ + A, where the chemical nature of the 'A' depends on the organism. The experiments conducted by Samuel Ruben and Martin Kamen by using radioactive isotopes helped to prove that the oxygen liberated during photosynthesis came from photolysis the water.

Thus, the correct answer is option B.