Active transport

• Active transport

  1. Specific molecule/ion binds to carrier protein

  2. ATP breaks down into ADP and Pi which release energy to change shape of carrier protein

  3. Molecule is deposited into cell and carrier protein reverted to original shape
• Factors affecting active transport

  • Speed of carrier protein (faster they work faster rate of active transport)
  • Number of carrier proteins present
  • Rate of respiration and availability of ATP
• Active transport process

  1. Carrier protein span plasma membrane and bind to molecule on one side of it
  2. Molecule binds to receptor sites on carrier protein
  3. Inside of the cell, ATP binds to protein, causing it to split into ADP and a phosphate molecule, protein molecule then changes shape and opens to opposite side of membrane
  4. molecule released to other side of membrane
  5. phosphate molecule released from protein = protien reverts to original shape
• Sodium-potassium pump

  • SOMETIMES MORE THAN ONE MOLECULE MAY BE MOBED IN THE SAME DIRECTION AT THE SAME TIME BY ACTIVE TRANSPORT, OCCASIONALLY THE MOLECULE IS MOVED INTO A CELL THE SAME TIME AS A DIFFERENT ONE IS BEING REMOVED
  • In a sodium potassium pump, sodium ions are actively removed from cell while potassium ions are actively taken in from surroundings