The chemical bond between oxygen and haemoglobin is

Options

A. Stable and reversible
B. Unstable and reversible
C. Stable and irreversible
D. Unstable and irreversible

Answer

To answer the question about the chemical bond between oxygen and hemoglobin, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hemoglobin**: Hemoglobin is a protein found in red blood cells that is responsible for transporting oxygen from the lungs to the tissues and facilitating the return of carbon dioxide from the tissues back to the lungs.

2. **Formation of Oxyhemoglobin**: When oxygen binds to hemoglobin, it forms a complex known as oxyhemoglobin. This occurs when oxygen molecules attach to the heme groups within the hemoglobin structure.

3. **Nature of the Bond**: The bond formed between oxygen and hemoglobin is not a strong covalent bond. Instead, it is a type of bond that allows for the easy release of oxygen when needed by the tissues.

4. **Stability of the Bond**: The bond between oxygen and hemoglobin is characterized as unstable. This means that the oxygen can be easily released from hemoglobin when the surrounding conditions (like partial pressure of oxygen) change.

5. **Reversibility of the Bond**: The bond is also reversible, meaning that oxygen can bind to hemoglobin and then be released without any permanent change to the hemoglobin structure. This is crucial for the efficient transport of oxygen in the body.

6. **Conclusion**: Based on the characteristics of the bond, we conclude that the chemical bond between oxygen and hemoglobin is unstable and reversible.

### Final Answer:
The chemical bond between oxygen and hemoglobin is **unstable and reversible**.

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