Question

All of the following are true concerning enzymes, except that they

A) are proteins.
B) function as biological catalysts.
C) lower the activation energy required for a reaction.
D) affect only the rate of a chemical reaction.
E) are consumed during the reaction.

Answer 1

Enzymes are highly specific catalysts that lower the activation energy of chemical reactions, increasing their rate without being consumed. They are not involved in changing the free energy (AG) of a reaction.

Step-by-step explanation:

Enzymes are large biological molecules, mostly composed of proteins, which are responsible for the thousands of metabolic processes that occur in living organisms. Enzymes are highly specific catalysts; they speed up the rates of certain reactions. Enzymes function by lowering the activation energy of the reaction they are catalyzing, which can dramatically increase the rate of the reaction.

It is important to remember that enzymes do not change the AG (free energy change) of a reaction. They only reduce the activation energy required to reach the transition state.

Like all catalysts, enzymes are not consumed during the reactions that they catalyze. Each enzyme is only capable of speeding up one or a few very specific reactions or types of reactions.