Digestion
Biology: AQA GCSE Higher, topic 2.2.6
Enzymes in Digestion
Digestive enzymes are made by specialised cells in the glands and the gut lining. They are then secreted (released) out of the body cells and into the cavity of the digestive system.
Breakdown large food molecules
- The digestive enzymes catalyse (speed up) the breaking down of large and insoluble molecules of food into smaller, soluble molecules that can be absorbed into the bloodstream.
- Digested molecules can be used to construct new carbohydrates, proteins and lipids in the body.
- Some glucose produced by digestion is used for respiration.
Enzymes in digestion
- The 3 main digestive enzymes are:
- Amylase
- Protease
- Lipase
Test yourself on Digestion
Why does the body break down large, insoluble food molecules into smaller, soluble molecules?
What happens to glucose produced by digestion that is not used for respiration?
What would happen if large, insoluble food molecules were not broken down by digestive enzymes?
Why must digested proteins be absorbed into the bloodstream before they can be used to build new proteins in the body?
What would happen if digestive enzymes were not secreted out of the gland cells into the gut cavity?