The iron free compound of haemoglobin is

Options

A. Globin
B. Haematin
C. Bilirubin
D. Haemotoxin

Answer

To solve the question regarding the iron-free compound of hemoglobin, we will analyze the options provided and understand the components of hemoglobin.

### Step-by-Step Solution:

1. **Understanding Hemoglobin**:
- Hemoglobin (Hb) is a metalloprotein responsible for transporting oxygen in the blood. It contains iron, which is essential for its function.

2. **Components of Hemoglobin**:
- Hemoglobin is composed of four polypeptide chains known as globin proteins. These chains are categorized into two types: alpha globin and beta globin.

3. **Identifying Iron-Free Components**:
- The globin proteins themselves do not contain iron. They are the protein part of hemoglobin and are responsible for the structure and function of hemoglobin but do not participate in oxygen binding directly.

4. **Evaluating the Options**:
- **Globin**: This is the protein part of hemoglobin and is indeed iron-free.
- **Hematin**: This is a derivative of heme that contains iron, so it is incorrect.
- **Bilirubin**: This is a breakdown product of heme and does not contain iron, but it is not a direct component of hemoglobin.
- **Hemotoxin**: This is a type of toxin and does not relate to hemoglobin directly.

5. **Conclusion**:
- The only option that is an iron-free component of hemoglobin is **globin**.

### Final Answer:
The iron-free compound of hemoglobin is **globin**.