Enzymes and food

Carbohydrates, proteins and lipids are large molecules that are needed by the body for growth, repair and metabolism. They are found in our food. These molecules are too large to pass from the intestine into the blood, so digestive enzymes break them down into smaller molecules. Once in the body, different enzymes use these raw materials to synthesise larger molecules.


Carbohydrates include glycogen, starch, sucrose and glucose.

The basic building block of a carbohydrate is a monosaccharide. This is simple sugar, such as glucose and fructose. Enzymes join monosaccharides together to form disaccharides (two monosaccharides) and polysaccharides (long chains of monosaccharides).

Carbohydrase enzymes break disaccharides and polysaccharides into monosaccharides (simple sugars). Carbohydrase enzymes are produced in your mouth (in saliva), pancreas and small intestine.


Proteins are large molecules made from amino acids joined together to form chains. They include enzymes, haemoglobin, collagen and keratin. Each protein has hundreds, or even thousands, of amino acids joined together in a unique sequence and folded into the correct shape. This gives each protein its own individual properties.

Protease enzymes are responsible for breaking down proteins in our food into amino acids. Then different enzymes join amino acids together to form new proteins needed by the body for growth and repair. Protease enzymes are produced in your stomach, pancreas and small intestine.


Lipids are fats and oils. Lipids are large molecules made from smaller units of fatty acids and glycerol.

Digestive enzymes such as lipase break down lipids in the diet into fatty acids and glycerol. Lipase enzymes are produced in your pancreas and small intestine.