active transport

• active transport moves ions/molecules from a region of lower concentration to a region of higher concentration
• active transport moves ions/molecules against the concentration gradient
• active transport requires metabolic energy provided by ATP
• cells that's undergo a lot of active transport have a lot of mitochondria
• active transport is used to move molecules/ions into and out of the cell but always against the concentration gradient
• active transport process:

  1. the ion/molecule binds to the carrier protein in the cell membrane at a receptor site
  2. ATP molecule binds to the carrier protein
  3. ATP molecule hydrolyses into ADP + phosphate releasing energy for AT
  4. the phosphate attaches to the carrier protein causing the protein to change shape
  5. ion/molecule is transported to the other side of the membrane where it is released
  6. the phosphate leaves the protein causing the protein to return to its original shape and ATP is reformed
• carrier proteins used in active transport are specific so each protein transports only one type of ion/molecule
• active transport only uses carrier proteins