Download Chapter 5

Chapter 5
Section 5.2 Active Transport
Active Transport

Movement of materials across a cell
membrane that requires a cell to expend
energy

Materials move UP their concentration
gradient
Cell Membrane Pumps

Moves substances up their concentration
gradient

Moves from an area of lower
concentration to an area of higher
concentration
Sodium-Potassium Pump

A special protein that transports Na+
ions and K+ up their concentration
gradients

To function properly, many animal cells
must have a higher concentration of Na+
ions outside the cell and a higher
concentration of K+ ions inside the cell
Endocytosis

Cells ingest external fluid,
macromolecules, and large particles
(including other cells)

Part of the cell forms a pouch around the
material then pinches off to form a
vesicle
Pinocytosis & Phagocytosis

Pinocytosis involves the transport of
solutes or fluids

Phagocytosis involves the movement of
large particles or whole cells
Exocytosis

Vesicles in the cytoplasm fuse with the
cell membrane and release their
contents out of the cell