Which of the following act as local messenger ?

Options

A. Carrier protein
B. Glycoprotein
C. Phospholipid
D. Glycolipid

Answer

**Step-by-Step Text Solution:**

1. **Understanding Messengers**: Begin by defining what messenger proteins are. Messenger proteins, also known as signaling proteins, are responsible for carrying messages or signals between cells. They facilitate communication between cells located in different parts of the body.

2. **Types of Messengers**: Recognize that there are different types of messengers. Some messenger proteins can act over long distances, while others act locally, meaning they only affect nearby cells. Local messengers are crucial for localized cell-to-cell communication.

3. **Identifying Local Messengers**: From the options provided (carrier protein, glycoprotein, phospholipid, and glycolipid), we need to identify which one acts as a local messenger.

4. **Examining Carrier Proteins**: Carrier proteins are known for their role in transporting specific molecules or ions across the cell membrane. They bind to these molecules and facilitate their movement through the lipid bilayer, releasing them on the other side. This process is limited to the cell membrane and its immediate surroundings.

5. **Conclusion**: Since carrier proteins operate within the vicinity of the cell and do not extend beyond the membrane, they are classified as local messengers. Therefore, the correct answer to the question is that **carrier proteins act as local messengers**.

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