9. Nutrients like starch, proteins and fats, are large, complex molecules. They cannot pass through the cell membrane. Nutrients like glucose and amino acids, are small, soluble molecules. They can pass through the cell membrane.
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11. “ Lock and key” hypothesis active sites Enzyme molecule Food molecule Enzyme-food complex Enzyme free to take part in next reaction. Two products leave the enzyme. Product X Product Y
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15. 26.5 The Human Digestive System salivary gland mouth cavity oesophagus stomach salivary glands pancreas colon rectum anus large intestine liver gall bladder small intestine