Question

Assertion A: ATP is used at two steps in glycolysis.

Reason R: First ATP is used in converting glucose into glucose-6-phosphate and second ATP is used in conversion of fructose-6-phosphate into fructose-1-6-diphosphate.

In the light of the above statements, choose the correct answer from the options given below:

Options

• Both A and R are true but R is NOT the correct explanation of A.

• A is true but R is false.

• A is false but R is true.

• Both A and R are true and R is the correct explanation of A.

Answer 1

Both A and R are true and R is the correct explanation of A.

Explanation:

• The glycolytic process uses ATP in two phases. The hexokinase enzyme converts glucose to glucose-6-phosphate, which requires the initial ATP. The enzyme phosphofructokinase converts fructose-6-phosphate to fructose-1,6-bisphosphate, which requires the second ATP.
• Both of these stages need the addition of a phosphate group to a substrate, which is supplied by ATP. Thus, both assertions A and R are true, and R is the correct explanation for A.