Question

How many ATP molecules are needed as an initial investment in the glycolytic cycle (normal glycolysis)?

• A. 1.
• B. 2.
• C. 3.
• D. 4.

Hint:

In glycolysis, 2 ATP molecules are invested during the energy investment phase, but a net gain of 2 ATP is achieved after the process.

Answer 1

The Correct Option is B

Step 1: Understanding ATP investment in glycolysis.
The glycolytic pathway begins with glucose being phosphorylated to form glucose-6-phosphate. This process requires energy in the form of ATP. A second ATP molecule is used to phosphorylate fructose-6-phosphate into fructose-1,6-bisphosphate. Step 2: ATP molecules used.
Two ATP molecules are consumed during the energy investment phase of glycolysis: One ATP is used in the conversion of glucose to glucose-6-phosphate. One ATP is used in the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate. \[ \therefore \text{The correct answer is: 2.} \]