Question

Which technique was used to prove that O₂ released is from water in plants?

Answer 1

Hydrolysis of water:

1. Hydrolysis is a part of photosynthetic processes.
2. Water molecules are broken down into hydrogen and hydroxyl ions.

H₂O → 2H⁺ + 2e^- + ¹/₂ O₂

Radioisotope techniques

1. By studying purple sulphur bacteria, Van Niel was the first scientist to demonstrate that photosynthesis is a light-dependent redox reaction.
2. In these redox reactions hydrogen from an oxidizable compound reduces carbon dioxide.
3. Using radioisotope techniques it was proved that H₂O is the hydrogen donor and is oxidized to O₂ in plant photosynthesis.