Which of the following statements about enzymes is not true?

Enzymes are biological catalysts that speed up chemical reactions without undergoing permanent changes themselves. Therefore, the idea that enzymes are destroyed during chemical reactions is not accurate. Instead, after facilitating a reaction, enzymes can be reused multiple times, as they remain intact and maintain their structure throughout the reaction process.

The other statements accurately represent the nature of enzymes: they act as catalysts, promoting reactions; almost all enzymes are indeed proteins, with a few exceptions being RNA-based ribozymes; and they do operate most efficiently at specific optimum pH levels, where their structure and function are best suited for the desired chemical activity.