Active transport

• Active transport steps

  1. Molecule binds to receptor complimentary in shape on the protein
  2. ATP binds to the carrier protein on the inside of the cell and is hydrolysed into ADP + Pi
  3. Causes carrier protein to change shape and release the molecule on the other side
  4. Phosphate ion released, protein returns to original shape
• Co-transport of glucose and sodium ions in the illium

  1. Sodium ions actively transported out the epithelial cell into the blood
  2. Reduces the sodium ion conc in the epithelial cell
  3. More sodium ions then move from the lumen into the epithelial cell
  4. Sodium ions and glucose then are co-transported into the epithelial cell
  5. Glucose moves from the epithelial cell to the blood