Final answer:
The kinetics of a thymidylate synthase-catalyzed reaction are affected by 5-Fluorouracil through decreased Km.
Step-by-step explanation:
The kinetics of a thymidylate synthase-catalyzed reaction are affected by 5-Fluorouracil through b) decreased Km.
5-Fluorouracil is a competitive inhibitor of thymidylate synthase, which means it competes with the substrate for binding to the active site of the enzyme. This leads to a higher concentration of the inhibitor being required to achieve the same reaction rate, resulting in a decrease in the apparent Km value.
5-Fluorouracil does not affect the Vmax value nor does it cause noncompetitive inhibition.