absorption

• Absorption definition?

  small molecules are carried into the blood across the epithelial cells lining the ileum
• villus?

  microvilli increase SA

  Artery brings oxygen

  veins help with circulation to maintain a gradient and glucose and amino acids are absorbed from these

  lacteal - needed for fat absorption
• epithelial cells -

  microvilli increase SA

  mitochondria produced ATP for AT

  golgi body modifies the FA and G back into triglycerides for absorption
• Co transport -

  sodium leaves the epithelial cells and moves into the blood by AT

  creates a concentration gradient from the lumen to the epithelial cells

  sodium and glucose both move from the lumen to the epithelial cells

  glucose moves into the blood by facilitated diffusion through a channel protein
• bile and micelles -

  micelles move to the cells of the small intestine

  when they come into contact with them, they break down into just FA and G

  they enter the epithelial cells across the cell membrane by diffusion

  to the endoplasmic reticulum where they're turned back to triglyceride

  to the golgi apparatus where they're modified with cholesterol and lipoproteins into a chylomicron

  leave the cell by exocytosis and go to the lacteal
• what is made when triglycerides are modified with cholesterol and lipoproteins?

  chylomicron