Co transport and absorption of glucose in the ileum

• Co-transporter


  A type of protein which can bind 2 molecules at one
• One of the molecules

  Moves down the concentration gradient
• The other molecule

  Moves against the concentration gradient
• Co-transport and absorption of glucose in the ileum

  1. Sodium ions are actively transported out of epithelial cell via sodium-potassium pump into the blood

  2. This maintains a higher concentration of sodium ions in the lumen of the intestine than inside of epithelial cells - creating a concentration gradient

  3. Sodium ions diffuse into epithelial cells down concentration gradient via a different cotransport (Sodium-glucose) protein in cell surface membrane

  4. As the sodium ions diffuse in through this second carrier protein they carry either amino acid or glucose molecules with them

  5. Glucose / Amino acids diffuse into blood down via facilitated diffusion