[Chapter 6: Cell Membranes]

Cell Transport, Part II
Old Books (5th Edition "Nemo" Books)
New Books (6th Edition Books)
Read pp. 114-123.
Read 113- 122.

Active Transport: requires large amounts of energy (ATP) to 'pump' materials against force of diffusion (low to high).

A. Endocytosis (bulk passage): move large polar molecules. This action requires energy input (ATP) by cell.

Animation: [Receptor-mediated Endocytosis]

Types of Endocytosis:

1) Phagocytosis: cell eating of large particles by formation of vacuoles.

Animations: [Phagocytosis] [Phagocytosis of Bacterium (Click on Normal Phagocytosis by Macrophage link!)[Phagocytosis #2] [Phagocytosis #3]

2) Pinocytosis: cell drinking, liquid material brought into cell by vacuole formation.

Animations: [Pinocytosis] [Pinocytosis]

B. Exocytosis: materials discharged from cell (vacuole passes plasma membrane to dump contents out of cell).

Animations:[Endocytosis & Exocytosis (McGraw Hill)] [Exocytosis] [ ---[Cellular secretion Animation] [Exocytosis #2] ---

C. Sodium-potassium pump. Moves 3 Na + out of cell & 2 K+ into cell. Both Na+ and K+ are moved from low to high concentration.

Animation: [Sodium/Potassium Pump#1] [Sodium-Potassium Pump #2] [Nerve Action Potential Animation]

[Na+/K+ Pump & Cotransport Online Lab (BioCourse.com)]

D. Proton pump (chemiosmosis): Uses ATP. moves protons (H+) out of cell from low to high concentration.

Animation: [Proton Pump (McGraw Hill)]

E. Cotransport: Movement of amino acids (aa) and sugar into cell from low to high concentration. Protons from proton pump provide energy to move the amino acids an sugar into the cell.

Animation: [Cotransport]

Animation: [Cotransport] (McGraw Hill]

Online Reviews of Passive & Active Transport:

A. Passive Transport



Osmosis in an Isotonic Environment: (www.cat.cc.md.us) -

Osmosis in a Hypertonic Environment:

Osmosis in a Hypotonic Environment:

Facillitated Diffusion (no ATP used......from high to low concentration)


Transport (In french, but does a good job illustrating diffusion, passage through protein channels, cotransport, Na/K pumps, endocytosis & exocytosis.)


B. Active Transport

Active Transport: (McGraw-Hill) - 4 Animations & Audio of CoTransport, Na/K Pump, Endocytosis & Exocytosis, and Proton Pump.

Sodium/Potassium Pump: (No text with it but a good animation of this important form of Active Transport)

CoTransport (passage of Na into the cell helps bring Glucose (G) in too!)

Sodium/Potassium Pump combined with Cotransport (The sodium/potassium pump is often coupled with Cotransport to power the active transport of glucose into a cell)


Phagocytosis: Shows both an animation as well as 2 short movie clips of amoebas ingesting other organisms via phagocytosis.

Receptor-mediated Endocytosis: The molecule to be moved into the cell must match up with a receptor on the membrane surface to be moved in.


Exocytosis: (BBC Education)