Pyruvic acid is oxidised into `"_______________"` before entering citric acid cycle.

Answer

To answer the question, "Pyruvic acid is oxidised into '_______________' before entering the citric acid cycle," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Pyruvic Acid**: Pyruvic acid is the end product of glycolysis, which is the metabolic pathway that breaks down glucose into smaller molecules.

2. **Role of Pyruvate Dehydrogenase**: Before pyruvic acid can enter the citric acid cycle (also known as the Krebs cycle), it must undergo a process called oxidation. This oxidation is facilitated by an enzyme known as pyruvate dehydrogenase.

3. **Formation of Acetyl CoA**: During the oxidation process, pyruvic acid is converted into acetyl CoA. This reaction also involves the reduction of NAD+ to NADH, which is an important electron carrier in cellular respiration.

4. **Linking to the Citric Acid Cycle**: The acetyl CoA produced from the oxidation of pyruvic acid then enters the citric acid cycle, where it combines with oxaloacetate to form citric acid, continuing the process of cellular respiration.

5. **Final Answer**: Therefore, the blank in the question can be filled with "acetyl CoA".

### Final Answer:
Pyruvic acid is oxidised into **acetyl CoA** before entering the citric acid cycle.

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