Which of the following statements is incorrect about enzyme catalysis?

Enzymes are highly reactive at high temperature

The correct answer is option 4. Enzymes are highly reactive at high temperature.

Enzymes are biological catalysts, typically proteins, that facilitate chemical reactions by lowering the activation energy required for the reaction to occur. Here's an explanation for each statement:

1. Enzymes are mostly proteinaceous in nature: This statement is correct. While there are some exceptions, the vast majority of enzymes are indeed proteins. Proteins are composed of amino acids arranged in specific sequences, and the structure of the protein determines its function as an enzyme

2. Enzyme action is specific: Enzymes are highly specific in their action. Each enzyme typically catalyzes only one type of chemical reaction or a specific group of closely related reactions. This specificity arises from the precise arrangement of amino acids in the enzyme's active site, which is complementary to the substrate(s) it acts upon.

3. Enzymes are denatured in ultraviolet rays: This statement is generally true. Ultraviolet (UV) radiation can disrupt the structure of proteins, including enzymes, through a process called denaturation. UV radiation can break chemical bonds and cause changes in the conformation of the protein, leading to loss of function.

4. Enzymes are highly reactive at high temperature: This statement is incorrect. While enzymes have an optimal temperature range at which they exhibit maximum activity (which varies depending on the enzyme), they are generally not highly reactive at very high temperatures. High temperatures can cause enzymes to denature, meaning their structure becomes disrupted, leading to a loss of catalytic activity. Enzymes function best within a specific temperature range, and extreme temperatures outside this range can impair their activity or render them completely inactive.

In summary, while enzymes are highly efficient catalysts that are specific in their action and primarily composed of proteins, they are susceptible to denaturation by factors such as high temperatures, including exposure to ultraviolet rays.