Question

Which of the following is true of enzymes?

i. they increase the rate of reaction by stabilizing the transition state
ii. they raise activation energy to shift the equilibrium to favor the products
iii. they lower activation energy by altering the products of a reaction

Answer 1

Enzymes speed up reactions by lowering activation energy and stabilizing the transition state, without altering the reaction's equilibrium or its products; enzymes remain unchanged after the reaction.

Step-by-step explanation:

Enzymes increase the rate of reaction by stabilizing the transition state and lower activation energy, but do not alter the products of a reaction or shift equilibrium to favor the products.

Enzymes are biological catalysts that accelerate chemical reactions by lowering the activation energy required to reach the transition state. This allows the reaction to proceed faster than it would without the enzyme. Enzymes achieve this by binding to their specific substrates at the active site, inducing a fit that brings the substrates into an optimal orientation for the reaction. This interaction can lead to the contortion of substrate bonds, making them easier to break and facilitating the formation of the transition state.

Enzymes may also provide an alternate route for the reaction with a lower activation energy, and certain amino acid residues within the enzyme can form covalent bonds with the substrate as part of the reaction process. Importantly, enzymes do not change the equilibrium of a reaction; they only make it faster to reach. They do not alter the products, nor do they get consumed or permanently altered by the reaction, as they return to their original state after catalyzing the reaction.