Pepsin & Trypsin
Biology: Cambridge International GCSE Supplement, topic 7.4.7
Pepsin & Trypsin
Pepsin and trypsin are both enzymes that break down proteins for absorption.
Proteins and digestion
- Enzymes are substances that speed up chemical reactions in the body.
- They help break down large food molecules into smaller ones that can be absorbed into the bloodstream.
- Proteases are a specific type of enzyme that breaks down proteins.
- Pepsin and trypsin are two important examples of proteases.
Pepsin
- Pepsin is a protease enzyme found in the stomach.
- It works best in a strong acidic condition (low pH, due to stomach acid).
- Its job is to break down protein into smaller chains of amino acids called peptides.
Trypsin
- Trypsin is another protease enzyme, released from the pancreas into the small intestine.
- It works best in alkaline conditions (higher pH, due to bile neutralising stomach acid).
- Trypsin continues the job of breaking down proteins and peptides into even smaller molecules (into individual amino acids), ready for absorption.
Why are both important?
- Pepsin starts protein digestion in the stomach.
- Trypsin completes the process in the small intestine.
- The final products, amino acids, are absorbed into the blood and used for growth and repair.
Test yourself on Pepsin & Trypsin
What type of enzymes are pepsin and trypsin?