A protein which exhibits β pleated structure is

Options

A. Fibroin
B. Haemoglobin
C. Enzyme
D. α-Keratin

Answer

To answer the question "A protein which exhibits β pleated structure is:", we will analyze the options provided and identify the correct one.

### Step-by-Step Solution:

1. **Understanding β Pleated Structure**:
- The β pleated sheet is a common motif in the secondary structure of proteins. It consists of beta strands connected laterally by at least two or three backbone hydrogen bonds, forming a sheet-like structure.

2. **Identifying the Options**:
- The options given are fibrin, hemoglobin, enzyme, and alpha-carotene. We need to evaluate which of these proteins exhibits a β pleated structure.

3. **Analyzing Each Option**:
- **Fibrin**: Fibrin is a fibrous protein that forms the basis of blood clots. It is known to have a β pleated sheet structure due to its arrangement of amino acids in anti-parallel strands.
- **Hemoglobin**: Hemoglobin is a globular protein responsible for oxygen transport in the blood. It primarily has an α-helical structure rather than a β pleated sheet.
- **Enzyme**: Enzymes can have various structures, but they do not specifically refer to a protein with a β pleated sheet structure.
- **Alpha-Carotene**: Alpha-carotene is a type of carotenoid and is not a protein; it does not exhibit a β pleated structure.

4. **Conclusion**:
- Based on the analysis, the protein that exhibits a β pleated structure is **Fibrin**.

### Final Answer:
The protein which exhibits β pleated structure is **Fibrin**.

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