Amutation causing an amino acid change in an enzyme that affects the turnover number kcat will also affect the as well.

Km as well.

Explanation:

Km ( Michaelis constant)  may be defined as the value or the substrate concentration at  which half the reaction has. This permits the enzyme to achieve the half Vmax.

The turn over number may be defined as the ratio of the Kcat to the Km. The mutation that affects the turn over number of the enzyme will also affect the Kcat as well as Km. As the Km is also dependent on the turnover number of the enzyme.

Thus, the answer is Km.

when a reversible reaction is occurring in both directions at the same rate; the products and reactants do not change in concentration. a chemical reaction where the compound is broken into its constituent parts.