How much energy is required in the energy investment phase of glycolysis?

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

Answer: (A)

Verified step by step guidance

1. Understand the process of glycolysis: Glycolysis is a metabolic pathway that converts glucose into pyruvate, releasing energy and producing ATP. It consists of two phases: the energy investment phase and the energy payoff phase.
2. Focus on the energy investment phase: This phase involves the initial steps of glycolysis where ATP is consumed to prepare glucose for breakdown. Specifically, ATP is used to phosphorylate glucose and its derivatives.
3. Identify the steps where ATP is used: In glycolysis, ATP is consumed in two key steps during the energy investment phase. First, ATP is used to convert glucose into glucose-6-phosphate. Second, ATP is used to convert fructose-6-phosphate into fructose-1,6-bisphosphate.
4. Calculate the total ATP used: Since ATP is used in two separate steps during the energy investment phase, you need to add the ATP molecules used in each step to find the total energy investment.
5. Review the options provided: Compare the calculated total ATP used in the energy investment phase with the options given in the problem to determine the correct answer.