Which of the following is not true of enzymes in $\mathrm{organic} \mathrm{chemistry} \mathrm{reactions}$?

• A. Enzymes are specific to substrates they bind to.
• B. Enzymes are consumed in the reactions they catalyze.
• C. Enzymes lower the $\mathrm{activation} \mathrm{energy}$ of reactions.
• D. Enzymes increase the rate of $\mathrm{chemical} \mathrm{reactions}$.

Answer: (B)

Verified step by step guidance

1. Understand the role of enzymes: Enzymes are biological catalysts that speed up chemical reactions without being consumed in the process. This means they can be used repeatedly in multiple reaction cycles.
2. Examine the specificity of enzymes: Enzymes are highly specific to the substrates they bind to, often fitting like a 'lock and key' with their specific substrate, which ensures that they catalyze only specific reactions.
3. Consider the effect of enzymes on activation energy: Enzymes lower the activation energy required for a reaction to proceed, making it easier for the reaction to occur and thus increasing the reaction rate.
4. Evaluate the statement about enzymes being consumed: Enzymes are not consumed in the reactions they catalyze. They remain unchanged after the reaction and can participate in subsequent reactions.
5. Identify the incorrect statement: Based on the understanding that enzymes are not consumed in reactions, the statement 'Enzymes are consumed in the reactions they catalyze' is incorrect.