Download PP-Active Transport Notes

Active Transport
Active Transport
Mechanisms
 Require cell energy
 Energy is provided by the cell
 Molecules can move against the conc
gradient (from low conc to high conc)
Types of Active
Transport
Mechanisms
 Proteins pumps
 Endocytosis
 Exocytosis
Protein Pumps
 Carrier proteins “pump” molecules across
the cell membrane
 Carrier proteins change shape as they
“pump” the ions/molecules across the
membrane
 Requires cell energy
 Ca pump-moves Ca ions from one part of a
skeletal muscle cell to another part so
the cell will contract
 Sodium-potassium pump-moves sodium
out of the cell and potassium into the cell
Endocytosis
 The engulfing of materials to bring into a
cell
 Pocket of cell membrane breaks off into
the cell=vesicle
 Phagocytosis=cell eating
 Pinocytosis=cell drinking
Exocytosis
Aldosterone
 Movement of large molecules out of the
cell
 Reverse of endocytosis
 Vesicles attach to the cell membrane and
open to allow the contents of the vesicle
out
 Used for waste materials