chapt 5.4 nutrient digestion

• protein

  difested by proteases
• protein

  no digestion in the mouth
• protein

  stomach protease digests protein into polypeptides in stomach
• protein

  intestinal protease digests proteins not digested by stomach protease into polypeptides
• proteins

  intestinal protease in small int digests polypeptides into amino acids that can be absorbed
• carb

  salivary amylase in the mouth digests starch to maltose, not much digestion happens as food does not stay in the mouth for long
• carb

  no digestion in the stomach
• carb

  in small int, pancreatic juice containing amylase digests the rest of the starch into maltose
• carb

  in small int, intestinal juices containing maltase digest the maltose into glucose, which is absorbed into the bloodstream
• carbs

  cellulose is not digested
• fats

  emulsification : breaking up of fats into tiny fat droplets
• fats

  bile produced in liver and stored in gallbladder contains bile salts
• fats

  bile salts emulsify fats in duodenum, increasing the surface area to vol ratio of the fats, allowing lipase to act on it more efficiently
• fats

  bile salts lower surface tension of fats, reducing attractive forces between fat molecules, breaking the fats up into tiny droplets