What is the net gain of ATP molecules in alcoholic and lactic acid fermentation , respectively?

Options

A. 2,4
B. 3,2
C. 2,3
D. 2,2

Answer

To determine the net gain of ATP molecules in alcoholic and lactic acid fermentation, we can follow these steps:

### Step 1: Understand the process of glycolysis
- Glycolysis is the first step in both alcoholic and lactic acid fermentation. In this process, one molecule of glucose is converted into two molecules of pyruvate.
- During glycolysis, a net gain of 2 ATP molecules is produced per glucose molecule.

### Step 2: Analyze lactic acid fermentation
- In lactic acid fermentation, the pyruvate produced from glycolysis is converted into lactate (lactic acid).
- This conversion does not produce any additional ATP; therefore, the total ATP gain from lactic acid fermentation remains 2 ATP.

### Step 3: Analyze alcoholic fermentation
- In alcoholic fermentation, the pyruvate is converted into ethanol and carbon dioxide.
- Similar to lactic acid fermentation, this conversion does not produce any additional ATP; thus, the total ATP gain from alcoholic fermentation also remains 2 ATP.

### Conclusion
- Both alcoholic fermentation and lactic acid fermentation yield a net gain of 2 ATP molecules from one molecule of glucose.

### Final Answer
The net gain of ATP molecules in alcoholic fermentation is **2**, and in lactic acid fermentation is also **2**.