Haemoglobin is

Options

A. Monomeric protein
B. Oligomeric protein
C. Chromoprotein
D. Both B and C.

Answer

**Step-by-Step Solution:**

1. **Understanding Hemoglobin**: Hemoglobin is a protein found in red blood cells responsible for transporting oxygen throughout the body. It consists of multiple polypeptide chains and a prosthetic group.

2. **Identifying the Options**:
- **A: Monomeric Protein**: This refers to proteins made up of a single polypeptide chain.
- **B: Oligomeric Protein**: This refers to proteins made up of more than one polypeptide chain.
- **C: Chromoprotein**: This refers to conjugated proteins that contain a prosthetic group, such as heme in hemoglobin.
- **D: Both B and C**: This option suggests that hemoglobin is both an oligomeric protein and a chromoprotein.

3. **Analyzing Hemoglobin Structure**:
- Hemoglobin is composed of four polypeptide chains: two alpha (α) subunits and two beta (β) subunits.
- Each of these subunits contains a heme group, which is the prosthetic group that binds oxygen.

4. **Determining the Correct Classification**:
- Since hemoglobin consists of multiple polypeptide chains, it qualifies as an oligomeric protein (Option B).
- Additionally, because it contains the heme group, it is classified as a chromoprotein (Option C).

5. **Conclusion**:
- Therefore, the correct answer to the question "Hemoglobin is" is **Option D: Both B and C**.

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