Hormones are called chemical signals that stimulate specific target tissues. Their specificity is due to the presence of signal receiving 'receptors' only in the respective target tissues. Where are these receptors present in case of hormones of protein nature

Options

A. Extra cellular matrix
B. Blood
C. Plasma membrane
D. Nucleus

Answer

To solve the question regarding the location of receptors for hormones of protein nature, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hormones and Their Function**:
- Hormones are chemical signals that regulate various physiological processes in the body. They exert their effects by binding to specific receptors located on target tissues.

2. **Identifying the Nature of Hormones**:
- Hormones can be classified into different categories based on their chemical structure, primarily into protein (or peptide) hormones and steroid hormones.

3. **Locating Receptors for Protein Hormones**:
- Protein hormones, which are made up of amino acids, typically cannot pass through the lipid bilayer of the cell membrane due to their size and polarity. Therefore, they bind to receptors that are located on the cell's surface.

4. **Understanding the Types of Receptors**:
- There are two main types of receptors:
- **Plasma Membrane Receptors**: These receptors are found on the surface of the cell membrane and are primarily for protein and peptide hormones.
- **Intracellular Receptors**: These receptors are located inside the cell, often in the nucleus, and are typically for steroid hormones.

5. **Conclusion**:
- Since the question specifically asks about hormones of protein nature, the receptors for these hormones are located on the **plasma membrane** of the target cells.

### Final Answer:
The receptors for hormones of protein nature are present on the **plasma membrane**.

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