What shape would a graph of reaction velocity versus pH have for an enzyme that uses both a proton donor and a proton acceptor during catalysis (both acid and base catalysis)?
A)Sigmoidal.
B)Hyperbolic.
C)Exponential.
D)Bell-shaped.
E)Linear.

Question

Quizplus · Accepted Answer

If an enzyme uses both a proton donor and acceptor during catalysis, the reaction velocity will be optimal at a specific pH, where both the donor and acceptor are in their preferred ionization states. The graph of reaction velocity versus pH for such enzymes will be bell-shaped, with a peak where the enzyme is most active at a specific pH. This is because the enzyme will be less active at pH values where either the donor or acceptor group is not in its optimal ionization state.

What Shape Would a Graph of Reaction Velocity Versus PH