Activation energy

For a chemical reaction to occur, bonds must be broken so new bonds can be formed- the energy required to break these bonds is called the activation energy

Enzymes work by lowering the activation energy to speed up reactions

This means less energy is needed to start the reaction and that reactions can happen at much lower temperatures

Meaning biochemical reactions needed to keep cells alive (metabolism) can occur at temps found in living cells → important because without this reactions would happen too slowly to sustain life as we know it