Question

Enzymes work by ___________.

1) raising the activation energy of a reaction and thus speeding up the reaction.
2) lowering the activation energy of a reaction and thus speeding up the reaction.
3) raising the ΔG of a reaction and thus speeding up the reaction.
4) lowering the ΔG of a reaction and thus speeding up the reaction.
5) changing the free energy of the products and speeding up the reaction.

Answer 1

Enzymes speed up biochemical reactions by lowering the activation energy required, allowing the reactants to convert into products more easily. They operate by binding reactants and optimizing their orientation to facilitate the reaction.

Step-by-step explanation:

How Enzymes Work

Enzymes are biological catalysts that speed up biochemical reactions inside living cells. They achieve this by lowering the activation energy required to start the reaction. Activation energy is a kind of barrier the reactants must overcome to transform into products. Enzymes do not raise the total energy change of the reaction (ΔG), nor do they affect the free energy of the products directly. Instead, by binding to reactant molecules, they reduce the energy needed for the reactants to come together and react.

By bringing reactants into a specific region on the enzyme, known as the active site, enzymes facilitate the correct orientation of these reactants. This optimized orientation and the alternative route provided by the enzyme with lower activation energy lead to an increased rate of reaction. This is particularly important in living organisms, where reactions must occur quickly and efficiently at cellular temperatures, without the need for additional heat.