Question

Number of ATP formed per molecule of oxygen used in respiration is

• A. 16
• B. 8
• C. 6
• D. 4

Answer 1

The correct option is C 6

Respiration is the process of breakdown of glucose with the help of molecular oxygen to produce ATP. It involves glycolysis and phosphorylation.

Glycolysis is the first step of glucose breakdown which takes place in the absence of oxygen and converts one molecule of glucose into two molecules of pyruvate. During this process, 4 molecules of ATP are produced and 2 molecules of ATP are consumed. Thus, net ATP production is 2 ATP.

Krebs cycle takes place in mitochondria and produces carrier molecules which pass through electron transport chain and produce 34 ATP molecules.

Thus, total ATP production is 36 from the oxidation of 6 molecules of oxygen. Hence, form one molecule of oxygen ATP produced is 6.

Thus, the correct answer is option C.