Question

For glycolysis to produce ATP when no oxygen is present, it is necessary for cells to convert _____ to _____.

A. ATP to NAD+
B. ATP to ADP
C. NADH to ATP
D. NADH to NAD+

Answer 1

To keep glycolysis going and produce ATP anaerobically, cells must convert NADH back to NAD+ by a process such as lactic acid fermentation. The correct answer to the student's question is D. NADH to NAD+.

Step-by-step explanation:

For glycolysis to produce ATP when no oxygen is present, it is necessary for cells to convert NADH to NAD+. This is because during glycolysis, NAD+ acts as an electron carrier and is reduced to NADH. The process of reducing NAD+ to NADH is essential for the continuation of glycolysis. Without the regeneration of NAD+, glycolysis would halt because there would be no NAD+ to accept electrons during the conversion of glyceraldehyde 3-phosphate (GAP) to 1,3-bisphosphoglycerate (1,3 bPG).

In the absence of oxygen, cells typically convert pyruvate to lactate via lactic acid fermentation. This reaction also regenerates NAD+ from NADH, allowing glycolysis to continue and produce ATP. The correct answer is D. NADH to NAD+, which is critical for maintaining the glycolytic pathway when oxygen is unavailable.

Answer 2

The answer is D. NADH to NAD+

When no oxygen is present, anaerobic respiration occurs.It is the only way to produce ATP in this condition.NAD+ is necessary because it is converted into NADH and at the same time ADP is converted to ATP in the reaction of pyruvate synthesis from glucose.Therefore, NADH must be converted to NAD+ in order to have NAD+ always present in the cell.