Which statement BEST describes how enzymes affect the speed of a metabolic reaction?

A.Enzymes increase the concentration of reactants, which increases the speed of the reaction.
B.Enzymes decrease the energy needed to start a reaction, which increases the speed of the reaction.
C.Enzymes replace the reactants in a chemical reaction, which decreases the speed of the reaction.
D.Enzymes prevent products from being converted back into reactants, which decreases the speed of the reaction.

1 answer

The statement that BEST describes how enzymes affect the speed of a metabolic reaction is:

B. Enzymes decrease the energy needed to start a reaction, which increases the speed of the reaction.

Enzymes act as catalysts by lowering the activation energy required for a reaction to occur, thereby accelerating the reaction rate without being consumed in the process.