Question: 114: What is the net gain of ATP when each molecule of glucose is converted to two molecules of pyruvic acid?
(1) Two
(2) Eight
(3) Four
(4) Six
Answer: Option (1)
Explanation:
The conversion of one molecule of glucose into two molecules of pyruvic acid occurs through the process of glycolysis.
During glycolysis, a total of four ATP molecules are produced by substrate-level phosphorylation.
However, two ATP molecules are consumed in the initial steps of glycolysis for the activation of glucose.
Thus, the net gain of ATP is calculated as 4 - 2 = 2.
Therefore, the net gain of ATP per molecule of glucose converted into two molecules of pyruvic acid is two ATP molecules.
Hence, the correct answer is Option (1).