To which part of Hb, `CO_(2)` binds?

Options

A. Haem
B. Amino group of globin
C. Iron of haem group
D. Carboxy group of globin

Answer

To determine the part of hemoglobin (Hb) to which carbon dioxide (CO₂) binds, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Hemoglobin**: Hemoglobin is a globular protein found in red blood cells (RBCs) and consists of two main components: the heme group and the globin protein chains (which include alpha and beta chains).

2. **Identify the Components**:
- **Heme Group**: Contains iron (Fe) and is primarily responsible for binding oxygen (O₂).
- **Globin Chains**: Composed of amino acids and includes amino groups and carboxyl groups.

3. **Function of Hemoglobin**: Hemoglobin is crucial for the transport of gases in the blood. Oxygen binds to the heme group, while carbon dioxide is transported differently.

4. **Binding of Carbon Dioxide**: Carbon dioxide does not bind to the heme group. Instead, it binds to the amino groups present in the globin chains of hemoglobin. This forms a complex known as carbaminohemoglobin.

5. **Conclusion**: Therefore, the part of hemoglobin to which carbon dioxide binds is the amino group of the globin chains.

### Final Answer:
Carbon dioxide binds to the amino group of the globin chains of hemoglobin.

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