Enzymes

Enzymes speed up reactions as they are a biological catalyst.

Enzymes use the lock and key model to show how enzymes synthesise (join together) or breakdown molecules.

In digestion, different molecules are broken down into different products:

• Proteins are broken down into amino acids.
• Carbohydrates (starch) are broken down into glucose molecules.
• Lipids (fats and oils) are broken down into fatty acids.

Enzymes which are often found in the body:

• Amylase - Breaks down starch to small sugars (e.g. maltose) in saliva and the small intestine.
• Catalase - Breaks down hydrogen peroxide into water and oxygen in most cells.
• Starch Synthase - Synthesises glucose into starch in plants.
• DNA Polymerase - Synthesises monomers into DNA in the nucleus.