Digestion
Digestion is the breaking down of foods and substances into their 'building blocks' before they can be absorbed through the wall of the 'gut'
- Physical digestion - mix food with saliva (contains enzymes), break food into smaller bits (increase surface area)
- Chain reaction muscles in oesophagus
Breaking down food substances:
Protein -> amino acid
Carbohydrates -> sugar
Lipids (fats/oils) -> fatty acids + glycerol
Digestion is speeded up by enzymes - chemical digestion