Animal organisation - digestion - AQAThe liver and digestion

The major nutrients required for a healthy diet are carbohydrates, proteins and lipids. The digestive system breaks down large molecules of food, which are then absorbed into the bloodstream.

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The liver and digestion

The does not secrete any , but it plays an important role in , and then processing food that have been .

The liver produces .

Bile:

  • , breaking them up physically into tiny droplets. Tiny droplets have a much larger surface area, over which lipases can work, than larger pieces, or drops of lipid.
Diagram illustrating how lipases work
  • Contains sodium hydrogencarbonate, which is an . It neutralises stomach acid and produces the for enzymes.
  • Is produced in the liver, but stored and concentrated in the .