Unit 4

• mouth


  where the food enters digestive system, contains salivary glands

  
• what does the salivary glands produce

  amylase and saliva, which help break down starch
• oesophagus


  tube which transports food from the mouth to stomach.

  
• what does the oesophagus cause

  peristalsis which allows food to move down into stomach
• what does the liver produce

  bile

  
• what does bile do

  neutralises the stomach pH and emulsifies fats

  
• gall bladder function


  stores and releases bile

  
• hydrochloric acid function


  maintains the stomachs acid conditions aswell as killing bacteria
• what does the stomach produce

  Protease enzyme, pepsin and hydrochloric acid

  
• What does the pancreas produce and where do they get released?

  amylase, protease, lipase into the small intestine
• what does the small intestine produce

  protease, amylase and lipase to complete the digestion process
• large intestine


  where excess water and nutrients are absorbed from foods

  
• mechanical digestion


  Physical breakdown of large pieces of food into smaller pieces
• chemical digestion


  breakdown of complex molecules into simple molecules
• Hydrolysis


  insertion of water molecules which breaks bonds
• 2 examples of a bond

  peptide, glycosidic
• condensation


  elimination of water molecules which cause components to join
• Gastrin


  hormone secreted in the stomach that stimulates secretion of HCl and increases gastric motility
• where is gastrin found

  lining of the stomach
• what produces gastrin


  G cells
• Where are G cells located?

  small intestine and stomach
• what 3 things cause gastrin to be released

  1. when proteins are present in the stomach

  2. when hypercalcaemia occurs

  3. when the stomach lining enlarges
• What inhibits gastrin release?

  somatostatin
• Somatostatin


  hormone that inhibits release of growth hormone and insulin
• 3 types of macronutrients

  carbohydrates, proteins, lipids
• carbohydrates function


  main source of energy
• protein function


  growth and repair of muscles and tissue
• lipids function


  insulates nerves while being a secondary energy source
• name 3 examples of a source of carbohydrates

  pasta, rice, potatoes
• name 3 examples of a source of protein

  chicken, eggs, nuts
• 2 types of lipids

  saturated and unsaturated
• saturated fats


  fats that are solid at room temperature
• unsaturated fats


  liquid at room temperature
• 2 examples of saturated fats


  butter and bacon
• 2 examples of unsaturated fats

  avocado, nuts
• Symptoms of carbohydrate deficiency

  muscle weakness and weight loss
• Symptoms of protein deficiency

  Anemia and Brittle nails
• symptoms of lipid deficiency

  dry skin, hunger
• Macronutrients


  Nutrients required in large quantities
• Micronutrients


  nutrients required in small amounts