Question

The enzyme RuBisCO has _________.

• A. more affinity for $C{O}_2$, than for $O_2$
• B. more affinity for $O_2$, than for $C{O}_2$
• C. equal affinity for both
• D. more affinity for sugars, than for $C{O}_2$

Answer 1

The correct option is A more affinity for $C{O}_2$, than for $O_2$

The active site of RuBisCO for carboxylation and oxygenation is the same. The enzyme has more affinity for $C{O}_2$ as compared to oxygen. Active oxygenation occurs only when $C{O}_2:O_2$ ratio favours it.

So the correct option is A.