Question

Which of the following systems do not follow Michaelis-Menten kinetics? (Select all that apply.)

a) The enzyme chymotrypsin.
b) An allosteric enzyme with [S] > Ky.
c) A simple enzyme when [S] > [E].
d) An allosteric enzyme with [S] > [E].
For an enzyme that obeys Michaelis-Menten kinetics, what is the reaction velocity, V. observed at the following substrate concentrations?
Express the result as a percentage of Vmax
(a) IF (S) = KM, then v/vₘₐₓ= ____%
(b) If [S] = 0.100KM, then v/vₘₐₓ=_____%

Answer 1

Systems with complex mechanisms like allosteric effects don't follow Michaelis-Menten kinetics. With [S]=0.100Km, the reaction velocity is 9.09% of Vmax.

Step-by-step explanation:

The systems that do not follow Michaelis-Menten kinetics typically involve complex mechanisms like allosteric regulation, cooperativity, or processes that cannot be simplified to the single-substrate, single-product scenario assumed by Michaelis and Menten. Examples include enzymes regulated by multiple allosteric effectors or enzymes that exhibit sigmoidal rather than hyperbolic kinetics.

When the substrate concentration [S] equals 0.100Michaelis-Menten constant (Km), it implies that the concentration is one-tenth of the Km value. According to the Michaelis-Menten equation, the velocity v will be v = Vmax[S] / (Km + [S]). If [S] is 0.100Km, then v = Vmax(0.100Km) / (Km + 0.100Km) = 0.1Vmax / 1.1. This simplifies to approximately 0.0909Vmax. To get this as a percentage of the maximum velocity (vmax), we multiply by 100, obtaining 9.09%.