How are enzymes involved in digestion?

Enzymes are involved in chemical digestion. When nutrients are ingested there are many different sized molecules across the various food groups. Some of these molecules are already small enough to be absorbed into the bloodstream, e.g. the monosaccharide glucose, but others need to be broken down into smaller molecules before they can be absorbed, e.g. the polysaccharide starch.

Enzymes break down these larger molecules, so that the nutrients can be absorbed into the blood stream and used.

Some enzymes and their actions that you need to know:

Amylase breaks down starch into maltose, in the mouth. (Pancreatic amylase also breaks down starch into maltose, in the small intestine)

Maltose is broken down into two molecules of glucose, by maltase.

Proteases (e.g. pepsin) break down proteins into amino acids, in the stomach and the small intestines.

Lipases (e.g. lipase) break lipids down into three fatty acid molecules and one glycerol molecule, in the small intestine.