One of the very important carrier proteins is

Options

A. insulin
B. myoglobin
C. myosin
D. fibrinogen

Answer

To determine which of the given options is a carrier protein, let's analyze each option step by step.

### Step 1: Understand the definition of carrier proteins
Carrier proteins are proteins that transport substances across cell membranes or within the body. They can carry various molecules, including ions, nutrients, and gases.

**Hint:** Remember that carrier proteins are involved in the transport of specific substances.

### Step 2: Analyze the first option - Insulin
Insulin is a hormone that regulates glucose levels in the blood. It is made up of 51 amino acids and plays a crucial role in metabolism but does not function as a carrier protein.

**Hint:** Consider the primary function of insulin and whether it involves transporting substances.

### Step 3: Analyze the second option - Myoglobin
Myoglobin is a muscle pigment protein that serves as an oxygen carrier. It binds oxygen in muscle cells and releases it when needed, making it a carrier protein.

**Hint:** Think about proteins that transport oxygen and their role in muscle function.

### Step 4: Analyze the third option - Myosin
Myosin is a motor protein involved in muscle contraction. It does not transport substances but instead facilitates movement within muscle fibers. Therefore, it is not a carrier protein.

**Hint:** Focus on the role of myosin in muscle activity rather than transport.

### Step 5: Analyze the fourth option - Fibrinogen
Fibrinogen is a protein involved in blood clotting. It is not a carrier protein; instead, it plays a role in the coagulation process.

**Hint:** Consider the function of fibrinogen in the context of blood and whether it transports substances.

### Conclusion
After analyzing all the options, the correct answer is **Myoglobin** (Option 2), as it is the only protein listed that functions as a carrier protein by transporting oxygen.

**Final Answer:** Myoglobin (Option 2) is one of the very important carrier proteins.

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