Heparin is

Options

A. Protein
B. Fat
C. Carbohydrate
D. Mucopolysacchride

Answer

### Step-by-Step Solution:

1. **Understanding Heparin**: Heparin is a substance that plays a crucial role in preventing blood coagulation or clotting. It is commonly referred to as an anticoagulant.

2. **Identifying the Nature of Heparin**: To classify heparin, we need to determine what type of biological molecule it is. The options provided are: protein, fat, carbohydrate, or mucopolysaccharide.

3. **Analyzing the Options**:
- **Protein**: Proteins are made up of amino acids and are involved in various functions in the body, such as catalyzing reactions and providing structure.
- **Fat**: Fats (lipids) are primarily involved in energy storage and insulation.
- **Carbohydrate**: Carbohydrates are sugars and starches that provide energy.
- **Mucopolysaccharide**: Mucopolysaccharides, also known as glycosaminoglycans, are long chains of sugar molecules that play a role in the structure and function of connective tissues.

4. **Conclusion**: Heparin fits the definition of a mucopolysaccharide, as it is a complex carbohydrate that has anticoagulant properties. Therefore, the correct classification of heparin is as a mucopolysaccharide.

5. **Final Answer**: Heparin is a mucopolysaccharide.