Which of the following are the main products of lactic acid fermentation in muscle cells?

• A. Glucose and oxygen
• B. Lactic acid and ATP
• C. Pyruvate and NADH
• D. Ethanol and carbon dioxide

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the concept of lactic acid fermentation. Lactic acid fermentation is an anaerobic process that occurs in muscle cells when oxygen is scarce. It allows cells to continue producing ATP by regenerating NAD⁺, which is needed for glycolysis.
2. Step 2: Recall the main reactants and products of lactic acid fermentation. The process starts with pyruvate, which is produced during glycolysis. Pyruvate is converted into lactic acid, and NAD⁺ is regenerated in the process.
3. Step 3: Note that ATP is produced during glycolysis, not directly during lactic acid fermentation. Glycolysis generates ATP before pyruvate enters the fermentation pathway.
4. Step 4: Eliminate incorrect options based on the process. Glucose and oxygen are not products of lactic acid fermentation; oxygen is absent in this anaerobic process. Ethanol and carbon dioxide are products of alcoholic fermentation, not lactic acid fermentation.
5. Step 5: Conclude that the main products of lactic acid fermentation in muscle cells are lactic acid and ATP, with ATP being produced indirectly during glycolysis.