Question

Carbon dioxide is used in the production of three carbon sugar by which of the following method?

• A. Photosystem- I
• B. Photosystem- II
• C. Electron transport chain
• D. Calvin cycle
• E. Citric acid cycle

Answer 1

The correct option is D Calvin cycle

Carbon dioxide is used in the production of three carbon sugar 3-phosphoglycerate, called as PGA. This PGA enters the Calvin cycle.

In the Calvin cycle, carbon atoms from CO${}_2$ are fixed and used to build three carbon sugars. This process is fueled by, and dependent on ATP and NADPH from the light reactions. When two of the three carbon sugars produced by the Calvin cycle come together, they can combine to form a glucose molecule. Glucose may be broken down to fuel cellular respiration or stored as starch for later use. The carbon atoms from glucose can also be used to build other types of biological molecules.