co-transport

Cards (9)

  • co-transporters are a type of carrier protein
  • they bind two molecules at a time
  • the concentration gradient of one of the molecules is used to move the other molecule against its concentration gradient
  • glucose is absorbed into the bloodstream in the small intestine
  • in the ileum, the concentration of glucose is too low for glucose to diffuse into the blood. so it's absorbed from the lumen of the ileum by co-transport
    1. sodium ions are actively transported out of the ileum epithelial cells into the blood by the sodium potassium pump, creating a concentration gradient between the lumen of the ileum and the epithelial cells
  • 2. this causes sodium ions to diffuse out of the lumen of the ileum into the epithelial cell, down the concentration gradient. done by the sodium glucose co-transporter proteins
  • 3. the co-transporter carries glucose into the cell along with sodium, increasing the concentration of glucose inside the cell
  • 4. glucose diffuses out of the cell, into the blood, by facilitated diffusion