Enzymes in Macronutrient Digestion
What Are Enzymes?
Enzymes are specialized proteins that act as biological catalysts in our digestive system. They speed up chemical reactions without being consumed in the process, making them essential for breaking down the food we eat into smaller, absorbable molecules.
NoteEach enzyme is highly specific and works only on particular substances (substrates) under specific conditions.
Key Digestive Enzymes and Their Functions
1. Carbohydrate-Digesting Enzymes
- Amylase
- Found in saliva (salivary amylase) and pancreas (pancreatic amylase)
- Breaks down complex carbohydrates into simpler sugars
- Starts working in the mouth and continues in the small intestine
- Maltase
- Converts maltose into glucose molecules
- Works in the small intestine
When you chew bread, salivary amylase immediately begins breaking down the starches. This is why if you hold bread in your mouth for a while, it starts to taste sweet as the complex carbohydrates are converted to simpler sugars.
2. Protein-Digesting Enzymes
- Pepsin
- Active in the stomach
- Breaks down proteins into smaller peptides
- Requires acidic conditions to function
- Trypsin and Chymotrypsin
- Released by the pancreas
- Further break down peptides into smaller amino acids
- Work in the small intestine
