How do enzymes and catalysts speed up chemical reactions?

• A. By increasing the concentration of reactants
• B. By lowering the activation energy required for the reaction
• C. By changing the equilibrium position of the reaction
• D. By increasing the temperature of the reaction

Answer: (B)

Verified step by step guidance

1. Understand that enzymes and catalysts are substances that increase the rate of a chemical reaction without being consumed in the process.
2. Recognize that the primary way enzymes and catalysts speed up reactions is by lowering the activation energy, which is the minimum energy required for a reaction to occur.
3. Activation energy can be visualized as a barrier that reactants must overcome to transform into products. By lowering this barrier, enzymes and catalysts make it easier for the reaction to proceed.
4. Note that enzymes achieve this by providing an alternative reaction pathway with a lower activation energy, often involving the formation of an enzyme-substrate complex.
5. It's important to clarify that enzymes and catalysts do not change the equilibrium position of a reaction or increase the concentration of reactants; they only affect the rate at which equilibrium is reached.