Question

Imagine that this experiment uses a mutant version that increases the enzyme's affinity, or ability, to bind its substrate. Using the graph as a comparison, what effect would the mutant version of the enzyme likely have on the KM?

Choose one:
A. The KM would not change at all (no effect).
B. The KM would move to the left (decrease).
C. The KM would move to the right (increase).

Answer 1

A mutant enzyme with increased substrate affinity would have a decreased Michaelis-Menten constant (KM), which would be represented on a graph as a shift to the left.

Step-by-step explanation:

If an experiment uses a mutant enzyme that increases the enzyme's affinity for its substrate, we would expect a change in the Michaelis-Menten constant (KM). The KM value is inversely related to the enzyme's affinity for its substrate; hence a higher affinity corresponds to a lower KM value.

Considering that the mutant enzyme binds its substrate more tightly, the KM would decrease. This means that in the graph comparing the wild-type enzyme to the mutant enzyme, the KM for the mutant enzyme would move to the left (decrease).