Which step of glycolysis requires pyruvic kinase, `Mg^(++),K^(+) and ADP`?

Options

A. Conversion of PEP into pyruvic acid
B. Conversion of 3PGA into 2PGA
C. Cleavage of Fructose 1-6 Biphosphate
D. All of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Glycolysis**: Glycolysis is a metabolic pathway that converts glucose into pyruvate, producing ATP and NADH in the process. It consists of several steps, each catalyzed by specific enzymes.

2. **Identifying the Enzyme**: The question specifically mentions "pyruvic kinase," which is an enzyme involved in the conversion of phosphoenolpyruvate (PEP) to pyruvic acid (pyruvate).

3. **Recognizing the Reaction**: The reaction catalyzed by pyruvic kinase involves the transfer of a phosphate group from PEP to ADP, resulting in the formation of ATP and pyruvate. This is a crucial step in glycolysis.

4. **Role of Cofactors**: The question also mentions the requirement of magnesium ions (Mg²⁺) and potassium ions (K⁺). These ions serve as cofactors that assist the enzyme pyruvic kinase in its catalytic activity.

5. **Identifying the Step**: The conversion of phosphoenolpyruvate (PEP) to pyruvic acid is the last step of glycolysis. Therefore, this step is the one that requires pyruvic kinase, Mg²⁺, K⁺, and ADP.

6. **Conclusion**: The correct answer to the question is the conversion of PEP into pyruvic acid, which is the last step of glycolysis.

**Final Answer**: The step of glycolysis that requires pyruvic kinase, Mg²⁺, K⁺, and ADP is the conversion of phosphoenolpyruvate (PEP) into pyruvic acid.

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