Hormones are called chemical signals that stimulate specific target tissues. Which is the corret location of these receptors in case of protein hormones?

Options

A. Extracellular matrix
B. Blood
C. Plasma membrane
D. Nucleus

Explanation

To answer the question about the correct location of receptors for protein hormones, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hormones**: Hormones are chemical signals that are secreted into the bloodstream and affect specific target tissues.

2. **Types of Hormones**: Hormones can be classified into different types based on their chemical nature, including protein (or peptide) hormones and steroid hormones.

3. **Protein Hormones**: Protein hormones are made up of amino acids and are generally hydrophilic (water-soluble). This property affects how they interact with cells.

4. **Receptor Location**: Since protein hormones are hydrophilic, they cannot easily pass through the lipid bilayer of the cell membrane. Therefore, they bind to receptors located on the surface of the target cells.

5. **Formation of Hormone-Receptor Complex**: When a protein hormone binds to its specific receptor on the plasma membrane, it forms a hormone-receptor complex. This complex then initiates a series of intracellular events that lead to the desired response in the target cell.

6. **Conclusion**: Based on the above points, the correct location of receptors for protein hormones is on the plasma membrane of the target cells.

### Final Answer:
The correct location of receptors for protein hormones is on the **plasma membrane**.

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