Three major ways for metabolism of pyruvic acid produced in glycolysis are

Options

A. Lactic acid fermentation, alcoholic fermentation and aerobic respiration
B. Oxaloacetic acid fermentation, lactic acid fermentation, aerobic fermentation, lactic acid fermentation, anaerobic fermentation
C. Alcoholic fermentation, oxaloacetic acid fermentation, citric acid fermentation
D. Citric acid fermentation, lactic acid fermentation, alcoholic fermentation.

Answer

**Step-by-Step Solution:**

1. **Understanding Glycolysis**: Glycolysis is the metabolic pathway that converts glucose into pyruvic acid, producing a small amount of ATP and NADH in the process. This occurs in the cytoplasm and is the first step in both aerobic and anaerobic respiration.

2. **Identifying Pyruvic Acid's Fate**: After glycolysis, the pyruvic acid can follow different metabolic pathways depending on the availability of oxygen.

3. **Lactic Acid Fermentation**: In the absence of oxygen (anaerobic conditions), pyruvic acid is converted into lactic acid. This process occurs in certain bacteria and animal cells (like muscle cells during intense exercise) and allows for the regeneration of NAD+, which is essential for glycolysis to continue.

4. **Alcoholic Fermentation**: Another anaerobic pathway is alcoholic fermentation, which occurs in yeast and some types of bacteria. In this process, pyruvic acid is converted into ethanol and carbon dioxide. This pathway is utilized in the production of alcoholic beverages and bread.

5. **Aerobic Respiration**: When oxygen is present, pyruvic acid enters the mitochondria and is converted into acetyl-CoA, which then enters the Krebs cycle (also known as the citric acid cycle). This process is highly efficient and produces a significant amount of ATP, along with NADH and FADH2, which are used in the electron transport chain.

**Final Answer**: The three major ways for the metabolism of pyruvic acid produced in glycolysis are:
1. Lactic acid fermentation
2. Alcoholic fermentation
3. Aerobic respiration (Krebs cycle)

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