5'2 Active Transport

1
5.2 Active Transport

• Active transport is the movement materials from
  low concentration to high concentration, using
  energy to do so.

2
Sodium-Potassium pump

• Carrier proteins that are used during Active
  transport are often called pumps.
• The sodium-potassium pump works to maintain a
  concentration gradient.
• Most cells require a higher amount of Na outside
  of the cell and K inside the cell.

3
Steps of Sodium-Potassium pump

• First three sodium bind to the pump on the inside
  of the cell.
• As the sodium binds to the protein a phosphate
  splits from an ATP to supply energy to the pump.
• The protein changes shape and moves the Sodium to
  the outside of the cell.
• On the outside of the cell the Potassium binds to
  the protein and the phosphate is released
  bringing the potassium into the cell.

4
Na, K, gradient

• As the pump works it creates a charged gradient,
  the pump moves three ions out and only two in.
• The difference in charge is important for nerve
  cells.

5
Endocytosis

• Is the process by which cells ingest fluids and
  large molecules by surrounding them with a
  membrane
• The membrane bound structure is called a vesicle.
• Pinocytosis is when fluids are ingested.
• Phagocytosis is when particles or cells are
  ingested

6
Exocytosis

• Is the process of releasing the contents of a
  vesicle to the outside of the cell.
• Exocytosis is used to release proteins and other
  large macromolecules out of the cell.