Question

An enzyme that follows Michaelis-Menten kinetics was determined to have a Vmax of 1.0 mM s−1, and a Km of 0.20 mM. If the concentration of enzyme that was used in the experiments that led to the above determinations was 10. nM, what is the value of the specificity constant (kcat/Km), and has this enzyme reached “catalytic perfection”?

kcat/Km = 5 × 10−9 M−1 s−1; the enzyme has not reached catalytic perfection

kcat/Km = 50 M−1 s−1; the enzyme has reached catalytic perfection

kcat/Km = 5 × 10−8 M−1 s−1; the enzyme has not reached catalytic perfection

kcat/Km = 5 × 109 M−1 s−1; the enzyme has reached catalytic perfection

kcat/Km = 5 × 108 M−1 s−1; the enzyme has reached catalytic perfection

kcat/Km = 5 M−1 s−1; the enzyme has not reached catalytic perfection

kcat/Km = 50 M−1 s−1; the enzyme has not reached catalytic perfection