Which substance is incorrectly matched with its mode of absorption in the gut?

Options

A. `Na^(+)` - Active absorption
B. Most of the glucose- Active absorption
C. `Cl^(-)` - Simple diffusion
D. Most of the amino acids -Facilitated transport

Answer

To solve the question of which substance is incorrectly matched with its mode of absorption in the gut, we will analyze each option provided.

### Step-by-Step Solution:

1. **Identify the Options**: We have four options to evaluate:
- (A) Sodium ion - Active absorption
- (B) Most of the glucose - Active absorption
- (C) Chloride ion - Simple diffusion
- (D) Most of the amino acids - Facilitated diffusion

2. **Evaluate Sodium Ion - Active Absorption**:
- Sodium ions are absorbed actively in the gut. This means they require energy (ATP) to be transported against their concentration gradient.
- **Conclusion**: This option is correctly matched.

3. **Evaluate Most of the Glucose - Active Absorption**:
- Glucose is primarily absorbed through active transport, often via co-transport with sodium ions. This process also requires energy.
- **Conclusion**: This option is correctly matched.

4. **Evaluate Chloride Ion - Simple Diffusion**:
- Chloride ions can move passively down their concentration gradient, which is classified as simple diffusion. This does not require energy.
- **Conclusion**: This option is correctly matched.

5. **Evaluate Most of the Amino Acids - Facilitated Diffusion**:
- While some amino acids can be absorbed via facilitated diffusion, the majority of amino acids are absorbed through active transport mechanisms, which require energy.
- **Conclusion**: This option is incorrectly matched, as most amino acids do not primarily use facilitated diffusion.

### Final Answer:
The substance that is incorrectly matched with its mode of absorption in the gut is **most of the amino acids - facilitated diffusion** (Option D).

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