The digestive system

• • Digestive enzymes convert food into small soluble molecules that can be absorbed by the bloodstream
• • Carbohydrases break down carbohydrates into simple sugars
  • Amalyse is a carbohydrase which breaks down starch
  • Amalyse is made in the salivary glands, pancreas, small intestine
• • Proteases convert proteins into amino acids
  • Proteases are made in the stomach (protease = pepsin), pancreas, small intensine
• • Lipases convert lipids into glycerol and fatty acids
  • Lipases are made in the pancreas, small intensine
• • The products of digestion are used to build new carbohydrates, lipids, proteins
  • Some glucose is used in respiration
• • Bile is made in the liver and stored in the gall bladder and is released into the small intestine
  • Bile is alkaline to neutralise hydrochloric acid from the stomach
  • Bile emulsifies fats to form small droplets which increase surface area
  • Alkaline conditions and large surface area increase the rate of fat breakdown by lipase
• • Salivary glands produce amalyse enzyme in saliva
• • Liver is where bile is produced
  • Bile neutralises acid and emulsifies fats
• • Stomach breaks down food with muscular walls
  • Stomach produces pepsin
  • Stomach produces hydrochloric acid to kill bacteria and to give PH 2 for pepsin to work
• • Pancreas produces protease, amalyse, lipase
  • Pancreas releases enzymes into small intensine
• • Small intestine produces protease, amalyse, lipase
  • Small intensine is where digested food is absorbed out of digestive system and into blood
• • Rectum is where faeces stored before excretion