Question

What is called as Warburgs effect on photosynthesis?

• A. Low rate of process due to $O_2$ supply
• B. Low rate of process due to $C{O}_2$ supply
• C. Both A and B
• D. None of the above

Answer 1

The correct option is A Low rate of process due to $O_2$ supply

The concentration of oxygen in the atmosphere is 21 percent by volume. An increase in oxygen concentration decreases photosynthesis and the phenomenon is called as Warburg effect. The explanation lies in the phenomenon of photorespiration. In C3 plants, the rate of day or light respiration is faster than dark respiration. This enhanced rate of respiration is called photorespiration. It operates in high light intensity, high oxygen concentration and high temperature. Here, oxygen competes with carbon dioxide for the oxidation of ribulose 1,5 bisphosphate (RUBP) or phosphoglycolic acid thus reducing the net fixation of carbon dioxide.

Therefore, the correct answer is option A.