Digestive Enzymes: Sources, Substrates, and Optima

What Are Digestive Enzymes?

Digestive enzymes are biological catalysts that speed up the breakdown of food substances into absorbable forms. Each enzyme acts on a specific substrate and works best at an optimal pH and temperature.

Here are some key digestive enzymes, their sources, substrates, and optimal conditions:

Key Digestive Enzymes

Enzyme	Source	Substrate	Optimal pH
Amylase	Salivary glands, pancreas	Starch	7.0 (neutral)
Pepsin	Stomach	Proteins	2.0 (acidic)
Lipase	Pancreas	Fats	8.0 (slightly alkaline)
Maltase	Small intestine	Maltose	6.0-7.0

Examples of Enzyme Action

• Amylase breaks down starch into maltose. It is found in saliva and pancreatic juice.
• Pepsin digests proteins into peptides in the stomach, where the environment is highly acidic.
• Lipase converts fats into fatty acids and glycerol in the small intestine.
• Maltase splits maltose into two glucose molecules in the small intestine.