1. Cell Structure and Function - Chapter 5
Membrane Dynamics
Using “X’s” draw a blood cell in a hypertonic environment.
Which way is the water going to move?
Why?
Label ECF and ICF

2. Which cell is in a hypertonic environment?

4. Membrane Dynamics Osmosis Diffusion ICF/ ECF
Cell Structure and Function - Chapter 5
Membrane Dynamics
Review Key Terms
Osmosis
Diffusion
ICF/ ECF
Hypertonic/ Hypotonic/ Isotonic
Be able to predict what will happen to water!

5. Diffusion across a membrane: Passive Transport No energy req’d down concentration gradient

6. Passive Transport: Facilitated Diffusion
The passive movement of molecules down its concentration gradient via a transport protein is called facilitated diffusion
Aquaporins

7. Facilitated Diffusion: Gated Ion Channels
Some transport proteins do not provide channels but appear to actually translocate the solute-binding site and solute across the membrane as the protein changes shape.

8. Active Transport Requires E (ATP) Against the concentration gradient UPHILL!

9. Using The Gradient’s Energy
HIGH concentration of H+ ions
Chemiosmosis
The movement of H+ ions down its concentration gradient is harnessed to the synthesis of ATP.
What organelle?
How can you concentrate the H+ ions?
What protein is shown?
LOW concentration of H+ ions

10. Through the Membrane

11. Transport with the Membrane E req’d
In phagocytosis, the cell engulfs a particle by extending pseudopodia around it and packaging it in a large vacuole.
In pinocytosis, “cellular drinking”, a cell creates a vesicle around a droplet of extracellular fluid
Receptor-mediated endocytosis is very specific in what substances are being transported.
This process is triggered when extracellular substances bind to special receptors, ligands, on the membrane surface, especially near coated pits.
This triggers the formation of a vesicle