The proteins that speed up certain chemical reactions are called enzymes. Enzymes are organic catalysts, which means that they increase the rate of a chemical reaction without being consumed in the reaction. Enzymes are typically globular proteins, and they work by providing a surface for the reactants to bind to, which allows the reaction to occur more quickly. They are highly specific, meaning each enzyme only catalyzes one specific reaction.

There are thousands of different enzymes in the human body, each with a different function. Some of the most important enzymes include:

- Amylase: Breaks down carbohydrates into sugars

- Lipase: Breaks down fats into fatty acids

- Protease: Breaks down proteins into amino acids

- DNA polymerase: Replicates DNA

- ATP synthase: Generates ATP, the energy currency of the cell