digestion and absorbtion

• What is the purpose of digestion?

  Turn large molecules into smaller ones
• Which part of the digestive system mixes food with acid and enzymes?

  Stomach
• Which part of the digestive system moves food from the mouth to the stomach?

  Oesophagus
• What is the role of the tongue in the digestive system?

  Shapes food into a ball for swallowing
• Which part of the digestive system takes water from undigested food?

  Large intestine
• What is the role of the liver in the digestive system?

  Makes bile
• Which part of the digestive system absorbs digested food?

  Small intestine
• Why do cells need digested nutrients?

  For energy and to make new molecules
• What is the role of hydrochloric acid in the stomach?

  Kills bacteria and provides acidic pH for protease
• Which enzyme in the stomach requires an acidic pH?

  Protease
• Where is bile made?

  Liver
• Where is bile stored?

  Gall bladder
• What is the role of bile in the small intestine?

  Emulsifies fats and neutralizes stomach acid
• What is the pH of bile?

  Alkaline
• How does the small intestine adapt for diffusion?

  Large surface area, short diffusion path, and good blood supply
• What are the folds of the small intestine surface called?

  Villi
• What is the effect of villi on the small intestine?

  Increases surface area
• What is the effect of the one-cell-thick wall of the villi?

  Shortens diffusion path
• What is the effect of the good blood supply to the villi?

  Maintains concentration gradient
• What is one use of glucose from digestion?

  Respiration
• What are the main components of the digestive system?

  • Mouth
  • Oesophagus
  • Stomach
  • Small intestine
  • Large intestine
  • Liver
  • Pancreas
  • Gall bladder
• What are the roles of hydrochloric acid and bile in the digestive system?

  • Hydrochloric acid: kills bacteria and provides acidic pH for protease
  • Bile: emulsifies fats and neutralizes stomach acid
• What are the adaptations of the small intestine for diffusion?

  • Large surface area
  • Short diffusion path
  • Good blood supply
• What are the uses of digested nutrients?

  • Making new carbohydrates, fats, and proteins
  • Energy production through respiration
• What is the role of the pancreas in the digestive system?

  Produces digestive enzymes
• What is the difference between mechanical and chemical digestion?

  Mechanical digestion breaks down food into smaller pieces, while chemical digestion breaks down molecules into smaller components
• What is the process of emulsification and its importance in fat digestion?

  • Emulsification: the breakdown of large fat droplets into smaller droplets
  • Importance: increases surface area for enzyme activity, allowing for more efficient fat digestion
• What is the role of enzymes in carbohydrate digestion?

  Break down carbohydrates into sugars
• What is the role of enzymes in protein digestion?

  Break down proteins into amino acids
• What is the role of enzymes in fat digestion?

  Break down fats into fatty acids and glycerol
• Why is pH important in enzyme activity?

  Enzymes have optimal pH ranges for activity
• What is the difference between the small and large intestines in terms of digestion and absorption?

  Small intestine: most digestion and absorption takes place; Large intestine: water absorption and storage of undigested food