The investment phase of glycolysis requires how many ATP molecules?

• A. 4 ATP
• B. 3 ATP
• C. 1 ATP
• D. 2 ATP

Answer: (D)

Verified step by step guidance

1. Understand the concept of glycolysis: Glycolysis is a metabolic pathway that converts glucose into pyruvate, releasing energy and producing ATP and NADH. It consists of two phases: the investment phase and the payoff phase.
2. Identify the investment phase: The investment phase of glycolysis involves the initial steps where ATP is consumed to phosphorylate glucose and its intermediates, preparing them for subsequent breakdown.
3. Recognize the specific steps in the investment phase: In glycolysis, two ATP molecules are used in the investment phase. The first ATP is used to convert glucose into glucose-6-phosphate, and the second ATP is used to convert fructose-6-phosphate into fructose-1,6-bisphosphate.
4. Use MathML to represent the ATP consumption: The reactions can be represented as follows: ${\mathrm{ATP}}_1+\mathrm{glucose}\to \mathrm{glucose}-6-\mathrm{phosphate}$ and ${\mathrm{ATP}}_2+\mathrm{fructose}-6-\mathrm{phosphate}\to \mathrm{fructose}-1,6-\mathrm{bisphosphate}$.
5. Conclude the investment phase: Summarize that the investment phase of glycolysis requires a total of 2 ATP molecules to proceed with the breakdown of glucose into pyruvate.