- A The first O2 molecule binds with the highest overall affinity
- B Binding of one O2 increases affinity for subsequent O2 molecules
- C Each subunit binds O2 fully independently of the others
- D O2 binding affinity decreases with each subsequent molecule bound
Correct answer: B. Binding of one O2 increases affinity for subsequent O2 molecules
Explanation: Positive cooperativity: binding of the first O2 causes conformational change that increases affinity for subsequent O2. This gives the sigmoidal O2 dissociation curve of hemoglobin.
Concept context
Carbohydrates, proteins, lipids, nucleic acids, and enzyme kinetics. Essential foundation for understanding metabolism.