1. Plasma Membrane,
Osmosis,
Diffusion
and
Water Balance

2. Membrane Structure & Function

3. Membrane structure, I Constructed of Phospholipids
Selective permeability
Amphipathic
polar vs. non-polar regions
hydrophobic & hydrophilic regions
“fluid mosaic” model
currently widely accepted

4. Phospholipid Structure

5. Membrane structure, II Phospholipids membrane fluidity Cholesterol
membrane fluidity and stabilization
“Mosaic” Structure
Integral proteins
trans-membrane proteins
transport materials
Peripheral proteins surface of membrane

6. Plasma Membrane

7. Diffusion, Osmosis, Facilitated Diffusion
High Concentration
Active-Need ATP (against or with gradient)
Active Transport
Passive (with gradient)
Diffusion, Osmosis, Facilitated Diffusion
Low Concentration

8. Diffusion movement of a substance from an area of high concentration of that substance to an area of low concentration of that substance.
Concentration gradient imbalance in concentration
Passive transport diffusion of a substance across a biological membrane without the need for energy
Osmosis the diffusion of water from an are of high concentration of water to an are of low concentration of water across a selectively permeable membrane

9. Water balance Osmoregulation control of water balance
Hypertonic higher concentration of solutes
Hypotonic lower concentration of solutes
Isotonic equal concentrations of solutes
Cells with Walls:
Turgid (very firm)
Flaccid (limp)
Plasmolysis
plasma membrane pulls away from cell wall

10. Specialized Transport
Transport proteins
Facilitated diffusion
passage of molecules and ions with transport proteins across a membrane down the concentration gradient
Active transport movement of a substance against its concentration gradient with the help of cellular energy