A cyanide molecule changes the rate of reaction due to

Options

A. competitive inhibition
B. non-competitive inhibition
C. allosteric modulation
D. feed back inhibition

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Cyanide:**
- Cyanide is a potent inhibitor of certain enzymes in the body, particularly those involved in cellular respiration.

2. **Identifying the Type of Inhibition:**
- The question asks how cyanide changes the rate of reaction. We need to determine if it acts as a competitive inhibitor, non-competitive inhibitor, allosteric modulator, or feedback inhibitor.

3. **Analyzing the Options:**
- **Competitive Inhibition:** This occurs when an inhibitor competes with the substrate for the active site of the enzyme.
- **Non-Competitive Inhibition:** This occurs when an inhibitor binds to an enzyme at a site other than the active site, reducing the enzyme's activity regardless of substrate concentration.
- **Allosteric Modulation:** This involves binding at a site other than the active site, which can either enhance or inhibit enzyme activity.
- **Feedback Inhibition:** This is a regulatory mechanism where the end product of a metabolic pathway inhibits an earlier step in the pathway.

4. **Cyanide’s Mechanism of Action:**
- Cyanide specifically inhibits cytochrome c oxidase, an enzyme in the electron transport chain, by competing with the substrate. This means it binds to the active site of the enzyme, preventing the normal substrate from binding.

5. **Consequences of Inhibition:**
- By inhibiting cytochrome c oxidase, cyanide halts the electron transport chain, leading to a cessation of ATP production and resulting in a condition known as hypoxic anoxia, where tissues receive blood but lack sufficient oxygen.

6. **Conclusion:**
- Therefore, the correct answer to the question is that cyanide changes the rate of reaction due to **competitive inhibition**.

**Final Answer:**
Cyanide changes the rate of reaction due to **competitive inhibition**.

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