A-Level Biology AQA 7402

3.3: Digestion and absorption

#3.3.1

During digestion, large biological molecules are hydrolysed to smaller molecules that can be absorbed across cell membranes.

#3.3.2

Digestion in mammals of:

  • carbohydrates by amylases and membrane-bound disaccharidases
  • lipids by lipase, including the action of bile salts
  • proteins by endopeptidases, exopeptidases and membrane-bound dipeptidases.
#3.3.3

Mechanisms for the absorption of the products of digestion by cells lining the ileum of mammals, to include:

  • co-transport mechanisms for the absorption of amino acids and of monosaccharides
  • the role of micelles in the absorption of lipids.
3.2
Gas exchange
3.4.1
Mass transport in animals
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