Active Transport Unit 2 Active Transport Cells move

Active Transport Unit 2

Active Transport Cells move material UP the concentration gradient from areas of low to high. USE ATP!!! Like walking UP a SLIDE

How does it work? Uses carrier proteins or pumps Pumps use ATP to move ions and large molecules across the membrane

Active Transport in Animals Allows signal transmission in nerve cells Maintains ion concentration in cells critical for homeostasis

Active Transport in Plants Enables roots to absorb nutrients against the concentration gradient Without active transport, nutrients would diffuse out of the roots.

Bulk Transport of STUFF Some molecules are too large to cross the membrane. Large molecules are packaged in vesicles by the Golgi and moved across membrane. Endocytosis & Exocytosis

Endocytosis Cell membrane folds into a POUCH that encloses the particles Pouch pinches off INSIDE Vesicle releases contents into the cytoplasm

Two Types of Endocytosis Phagocytosis—Cell engulfs a food particle or other cells “CELL EATING” Vesicle fuses with a lysosome How cells get rid of bacteria Pinocytosis– Cells engulf liquid/fluid “CELL DRINKING”

Exocytosis Opposite of endocytosis Waste and cell products LEAVE the cell Proteins made in the cell are packaged in the Golgi, and secreted out of the cell “Cell throwing up”