The first phase in the breakdown of glucose in animal cell is

Options

A. Fermentation
B. Krebs cycle
C. Glycolysis
D. E.T.S.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the first phase in the breakdown of glucose in animal cells.

2. **Identifying the Process**: The breakdown of glucose occurs through a series of metabolic pathways. The primary pathways include glycolysis, the Krebs cycle (also known as the citric acid cycle), and fermentation.

3. **Focusing on Glycolysis**: Glycolysis is the first step in the breakdown of glucose. It occurs in the cytoplasm of the cell and involves a series of ten enzymatic reactions.

4. **Conversion of Glucose**: During glycolysis, one molecule of glucose (a 6-carbon compound) is converted into two molecules of pyruvate (a 3-carbon compound).

5. **Importance of Glycolysis**: Glycolysis is a common pathway for both aerobic (in the presence of oxygen) and anaerobic (in the absence of oxygen) respiration.

6. **Conclusion**: Therefore, the first phase in the breakdown of glucose in animal cells is glycolysis.

### Final Answer:
The first phase in the breakdown of glucose in animal cells is **glycolysis**.

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