digestive system

• digestive system has two main roles:

  • digestion = process of breaking down large food molecules into smaller molecules
  • absorption = process of absorbing these small food molecules into the body
• • The salivary glands in our mouth release saliva which lubricates the food and makes it easier to swallow
  • It also contains the enzymeamylase, which breaks down starch intomaltose
• name of the tube that carries food from the mouth to the stomach:

  • oesophagus
• 3 roles of the stomach:

  • The stomach contracts its muscular walls to churn and mix the food. 
  • It produces pepsin, which is a type of protease enzyme, and breaks proteins down into amino acids.
  • It produces hydrochloric acid, which a) provides the right pH for pepsin to function, and b) kills microorganisms. 
• roles of the bile:

  • bile is made by the liver
  • it is stored in the gallbladder
  • after we eat, bile is released into the small intestine where it
  • emulsifies lipids
  • neutralises the acid in the stomach
• where enzymes does the pancreas produce:

  • amylase
  • protease
  • lipase
• what enzymes does the small intestine produce:

  • amylase
  • protease
• main role of the large intestine:

  • absorbs water