How do enzymes work?

Enzymes are molecules in the body that break down specific substrates which can then be used for energy or stored. An enzyme contains an active site that is complementary in shape to the substrate being broken down. The substrate collides with the enzyme and fits into the active site, where bonds are broken in the substrate and it is metabolized. This mechanism is known as the lock and key mechanism. Amylase is an enzyme found in our salivia which is used to break down starch into glucose. Protease breaks down proteins into amino acids and lipase breaks down fat into lipids and fatty acids.