Pyruvic acid is formed at the end of

Options

A. Calvin cycle
B. Glycolysis
C. Kreb's cycle
D. All of the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which process results in the formation of pyruvic acid. We need to analyze the options provided: Calvin cycle, glycolysis, Krebs cycle, and all of the above.

2. **Analyzing Each Option**:
- **Option 1: Calvin Cycle**: This cycle is part of photosynthesis in plants and is responsible for converting carbon dioxide and water into glucose. Pyruvic acid is not produced in this cycle.
- **Option 2: Glycolysis**: This is a metabolic pathway that breaks down glucose into pyruvic acid. It occurs in the cytoplasm of cells and is the primary process in both aerobic and anaerobic respiration.
- **Option 3: Krebs Cycle (Citric Acid Cycle)**: This cycle occurs after glycolysis and involves the conversion of pyruvic acid into citric acid. Therefore, pyruvic acid is not formed here; it is actually consumed.
- **Option 4: All of the Above**: Since only glycolysis produces pyruvic acid, this option is incorrect.

3. **Conclusion**: Based on the analysis, the correct answer is **Option 2: Glycolysis**. Pyruvic acid is specifically formed at the end of the glycolysis pathway.

**Final Answer**: Pyruvic acid is formed at the end of **glycolysis**.

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