Fill in the blanks : (1) ………… `overset"Pepsin" to` (2) ………….

Explanation

**Step-by-Step Solution:**

1. **Identify the Enzyme and its Function**: The question refers to the enzyme "pepsin," which is a gastric enzyme secreted in the stomach. It is responsible for breaking down proteins.

2. **Understand the Form of Pepsin**: Pepsin is secreted in an inactive form called "pepsinogen." This inactive form is converted into the active enzyme pepsin by the action of hydrochloric acid in the stomach.

3. **Identify the Substrate**: The substrate that pepsin acts upon is "proteins." These are complex molecules made up of long chains of amino acids.

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