ORGANISATION

• what is a tissue

  group of cells with similar structure and function
• what is a organ

  group of tissues working together for a specific function
• what is a organ system

  group of organs working together to form organism
• food contains what 3 nutrients

  • carbohydrates
  • protein
  • lipids
• what happens during digestion

  large molecules broken down to small molecules by enzymes --> absorbed into bloodstream
• lable diagram

  .

  A) mouth

  B) oesophagus

  C) stomach

  D) pancreas

  E) large intestine

  F) liver

  G) small intestine

  H) gallbladder

  
• what happens in mouth in digestive system

  enzymes in saliva digest starch into sugar
• what happens in the stomach in digestive system

  • enzymes begin digestion of protein
  • hydrochloric acid helps enzymes digest
• what does the churning action of the stomach do to food

  turns to liquid --> increases surface area for enzymes to digest
• what does liver release

  bile
• what does bile do

  • nuetralises acid from stomach
  • emulsifies fats
• what takes place in small intestine

  small molecules absorbed into bloodstream by diffusion or active transport
• what happens in large intestine during digestion

  water absorbed into bloodstream
• what are the products of digestion used for in body

  build new carbohydrates, lipids and proteins
• what is some glucose used for

  respiration
• what enzymes digests protein

  protease
• what enzyme breaks down starch

  amylase
• what enzyme breaks down carbohydrates

  carbohydrase
• what enzyme breaks down lipids

  lipase
• what are enzymes

  • catalyse chemical reactions --> arents used up
  • have active site where substrate attaches to
• what is the lock and key theory

  enzymes are specific --> substrate MUST fit perfectly to active site to break down
• where is protease produced

  • stomach
  • pancreas
  • small intestine
• what are proteins

  long chains of amino acids
• what happens when you digest proteins

  converted back to amino acids --> absorbed --> made into human proteins
• where is amylase produced

  • salivary glands
  • pancreas
  • small intestine
• where are lipase produced

  • pancreas
  • small intestine
• what are lipids made of

  1 glycerol and 3 fatty acids
• where is bile made

  liver
• where is bile stored

  gall bladder
• what pH is bile

  alkaline
• what happens when you increase temp with enzymes

  activity of enzyme increases --> reaction = faster as more collisions
• what is optimal temperature

  enzymes work at fastest possible rate
• what happens if you continue increasing temp to enzyme

  denature
• what is optimal temp for human enzymes

  37
• what is meant by denature

  active site changes and no longer fits substrate
• if you make pH more acidic or alkaline what happens to enzyme

  denatures
• why is small intestine so long

  large surface area for absorption of digesteion products
• what increases the surface area of small intestine

  villi and microvilli
• why villi have good blood supply

  • rapidly removes products of digestion
  • --> increases concentration gradient
• why do villi have short membrane

  short diffusion path