Question

Which of the following features distinguishes myoglobin from hemoglobin?

• A. Presence of heme prosthetic group
• B. Ability to bind to oxygen
• C. Molecular size and allostery
• D. Hemoglobin is found only in humans

Hint:

Hemoglobin = 4 subunits (Teamwork/Allostery). Myoglobin = 1 subunit (Solo).

Answer 1

The Correct Option is C

Step 1: Concept
Myoglobin and Hemoglobin are both oxygen-binding proteins but serve different roles (storage vs. transport).

Step 2: Analysis
Both contain heme and bind oxygen. However, myoglobin is a monomer (smaller size), while hemoglobin is a tetramer.

Step 3: Reasoning
Due to its multi-subunit structure, hemoglobin exhibits allostery (cooperative binding), which myoglobin, being a single subunit, cannot do.

Step 4: Conclusion
The primary distinctions are their molecular size and the presence of allosteric regulation in hemoglobin. Final Answer: (C)