Which of the following statements about myoglobin is correct?

• A. Myoglobin is a tetrameric protein like hemoglobin.
• B. Myoglobin binds oxygen with higher affinity than hemoglobin.
• C. Myoglobin is primarily found in red blood cells.
• D. Myoglobin exhibits cooperative binding of oxygen.

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the structure of myoglobin. Myoglobin is a monomeric protein, meaning it consists of a single polypeptide chain, unlike hemoglobin, which is tetrameric (composed of four subunits). This eliminates the first option as incorrect.
2. Step 2: Analyze the oxygen-binding properties of myoglobin. Myoglobin binds oxygen with higher affinity than hemoglobin, especially at lower oxygen concentrations. This is due to its role in storing oxygen in muscle tissues rather than transporting it. This makes the second statement correct.
3. Step 3: Evaluate the location of myoglobin. Myoglobin is primarily found in muscle tissues, not red blood cells. Hemoglobin, on the other hand, is found in red blood cells. This eliminates the third option as incorrect.
4. Step 4: Consider the binding mechanism of myoglobin. Myoglobin does not exhibit cooperative binding of oxygen because it is a monomeric protein. Cooperative binding is a property of hemoglobin due to its tetrameric structure, where binding of oxygen to one subunit affects the binding affinity of the other subunits. This eliminates the fourth option as incorrect.
5. Step 5: Conclude that the correct statement is: 'Myoglobin binds oxygen with higher affinity than hemoglobin,' based on its structure and function in muscle tissues.