Question

The net equation for aerobic glycolysis is

• A. Glucose+2ATP \(\rightarrow\) 2 lactate+2ADP+2P_i
• B. Glucose+2ADP+2P_i+2NAD⁺ \(\rightarrow\)2 pyruvate+2ATP+2NADH+2H2O+4H⁺
• C. Glucose+2ADP+2P_i \(\rightarrow\) 2 pyruvate+2ATP+2H₂O
• D. Glucose + 2 NAD⁺ + 2 ADP + 2 P_i \(\rightarrow\) 2 Pyruvate + 2 NADH + 2 H⁺ + 2 ATP + 2 H₂O

Answer 1

The Correct Option is D

The process in question is aerobic glycolysis, also known as the Embden-Meyerhof-Parnas (EMP) pathway. It is a crucial metabolic pathway that converts glucose into pyruvate, utilizing oxygen and generating energy in the form of ATP. Let's examine the chemical reactions in this process and arrive at the correct net equation.

Step 1: Understand Glycolysis

Glycolysis involves several enzyme-catalyzed reactions that transform one molecule of glucose into two molecules of pyruvate, producing ATP and NADH in the process.

Step 2: Breakdown of Reactions

• 1 glucose molecule is broken down to form 2 pyruvate molecules.
• A net gain of 2 ATP molecules is achieved (4 ATP are produced, 2 are consumed).
• 2 NAD⁺ molecules are reduced to 2 NADH.

Step 3: Analyze Each Option

• \(Glucose+2ATP \rightarrow 2 lactate+2ADP+2P_{i}\) - This describes anaerobic glycolysis, where lactate is the end product, not pyruvate.
• \(Glucose+2ADP+2P_{i}+2NAD^{+} \rightarrow 2 pyruvate+2ATP+2NADH+2H2O+4H^{+}\) - Missing the correct stoichiometry of reactants and products.
• \(Glucose+2ADP+2P_{i} \rightarrow 2 pyruvate+2ATP+2H_{2}O\) - Lacks NAD⁺ and NADH, missing in glycolytic reactions.
• \(Glucose + 2 NAD^{+} + 2 ADP + 2 P_{i} \rightarrow 2 Pyruvate + 2 NADH + 2 H^{+} + 2 ATP + 2 H_{2}O\) - Correct rendition of net reaction accounting for all substrates and products.

Conclusion:

The correct answer is: Glucose + 2 NAD⁺ + 2 ADP + 2 P_i \(\rightarrow\) 2 Pyruvate + 2 NADH + 2 H⁺ + 2 ATP + 2 H₂O

This equation accurately represents the net reaction of aerobic glycolysis, accounting for the conversion of glucose into pyruvate with the generation of ATP and NADH.