Ap Biology Mechanisms For Transport Across Cell Membranes

Front 1

Diffusion: Direct

Back 1

Random molecular motion causes the movement of non polar molecules to lower concentration

Front 2

Diffusion: Protein Channel

Back 2

Polar molecules move through a protein channel; movement goes to low concentration

Front 3

Facilitated Diffusion: Protein Carrier

Back 3

Molecule binds to carrier protein in membrane and if transported across; movement is to low concentration

Front 4

Osmosis: Aquaporins

Back 4

Diffusion of water across the membrane by osmosis requires osmotic gradient

Front 5

Active Transport: Na+/K+ pump

Back 5

Carrier uses energy to move a substance across a membrane against its concentration gradient

Front 6

Active Transport: Coupled Transport

Back 6

Molecules transported across a membrane against their concentration gradients by the contransport of Na+ ions/protons down their concentration gradients

Front 7

Endocytosis: Phactogytosis

Back 7

Particle is engulfed by membrane, which folds around it and forms a vesicle

Front 8

Endocytosis: Pinocytosis

Back 8

Fluid droplets are engulfed by membrane; which forms vesicles around them

Front 9

Endocytosis: Receptor-Mediated Endocytosis

Back 9

Endocytosis triggered by a specific receptor, forming clathrin-coated vesicles

Front 10

Exocytosis: Membrane Vesicle

Back 10

Vesicles fuse with plasma membrane and export contents