All of the following statements about enzymes are true except
(a) a single enzyme molecule can be used over and over again.
(b) most enzymes are highly specific with regard to the reactions they catalyze.
(c) some enzymes contain an essential nonprotein component.
(d) enzymes can function only within living cells.
(e) most enzymes are denatured by high temperatures.

(D) Enzymes can function only within living cells.

Explanation:

Enzymes are biological molecules that are proteinous in nature and speed up the rate of biological reactions.

Option A is true because enzymes are not used up or changed when they are used to catalyze reactions

Option B is true. Enzymes are very specific with regards to the reactions they take part in.

Option C is true. Some enzymes contain non-protein component that assist them in their functioning. These non-protein components are called co-factors.

Option E is true. Because enzymes are proteinous in nature, they can be destroyed/denatured by high temperatures.

The only untrue option is D. Some enzymes can function outside living cells. For example, the enzymes involved in digestion can function not just within living cells but also outside it. The functions of some of the digestive enzymes can be demonstrated in the laboratory.

The correct option is D.

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