1. Cellular Transport Notes

2. Structure of the Cell Membrane
Outside of cell
Carbohydrate
chains
Proteins
Lipid
Bilayer
Transport
Protein
Phospholipids
Inside of cell
(cytoplasm)
Animations
of membrane structure
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3. Types of Cellular Transport
Animations of Active Transport & Passive Transport
high
low
Weeee!!!
Passive Transport
cell does NOT use energy
Diffusion
Facilitated Diffusion
Osmosis
Active Transport
cell does use energy
NA+ K Pump
Endocytosis
Exocytosis
high
low
This is gonna be hard work!!

4. Passive Transport (HighLow) no energy required
molecules move randomly
Molecules spread out from an area of high concentration to an area of low concentration.
(HighLow)
Food coloring in water demo

5. 3 Types of Passive Transport
Diffusion
Facilitative Diffusion – diffusion with the help of transport proteins
Osmosis – diffusion of water

6. Simple Diffusion Animation
random movement of particles from an area of high concentration to an area of low concentration.
(High to Low)
Diffusion continues until all molecules are evenly spaced = equilibrium

7. Facilitated diffusion (Channel Protein) Diffusion (Lipid Bilayer)
diffusion of specific particles through transport proteins found in the membrane
Transport Proteins are specific – they “select” only certain molecules to cross the membrane
Transports larger or charged molecules
Facilitated diffusion (Channel Protein)
Diffusion (Lipid Bilayer)
Carrier Protein

8. Facilitated Diffusion
Glucose
molecules
Cellular Transport From
High
High Concentration
Channel Proteins animations
Cell Membrane
Low Concentration
Protein
channel
Low
Transport Protein
Through a 
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9. Osmosis Osmosis animation
diffusion of WATER through a semi- permeable membrane
Water moves from high to low concentrations
Water is so small and there is so much of it the cell can’t control it’s movement through the cell membrane.
Water moves freely through pores.
Solute (green) too large to move across.

10. Tonicity
The concentration of solutions (usually one inside a cell and the other outside the cell, that determine direction and amount of diffusion

11. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
There is less solutes outside the cell than there is inside the cell (hypo = low/less)
Result: Water moves from the solution to inside the cell (to dilute the solutes)- Cell Swells and bursts open (cytolysis)!

12. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
Hypertonic Solution
There is more solutes outside the cell than there is inside the cell (hyper = higher/more)
shrinks
Result: Water moves from the cell into the solution (to dilute the solutes) Cell shrinks (Plasmolysis)!

13. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
Isotonic Solution
The concentration of solutes in the solution is equal to the concentration of solutes inside the cell.
Result: Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium)

14. B C A What type of solution are these cells in? Hypertonic Isotonic
Hypotonic

16. Active Transport (Low  High) cell uses energy
actively moves molecules to where they are needed
Movement from an area of low concentration to an area of high concentration
(Low  High)

17. Sodium / Potassium Pump (Na+ / K+)
Sodium Potassium Pumps (Active Transport using proteins)
Pumps are carrier/transport proteins that require energy to move substances UP their concentration gradient.
Sodium / Potassium Pumps are important in nerve responses.
Transports 3 Na ions out of cell and 3 K ions into the cell
Prevents Na ions from building up in the cell which would lead to osmosis into the cell and eventual bursting of the cecll
Protein changes shape to move molecules: this requires energy!

19. Mass Transport Across a Membrane
Vesicles
Many substances, such as proteins, polysaccharides, and even bacteria, are too large to be transported by carrier proteins altogether.
Instead, they cross the cell membrane in vesicles, which are membrane-bound (lipid bi-layer) sacs.
vesicles can bud off from the membrane, fuse with it, or fuse with other vesicles.

20. Endocytosis taking bulky material into a cell Uses energy
Cell membrane in-folds around food particle
“cell eating”
forms food vacuole & digests food
This is how white blood cells eat bacteria!

21. Endocytosis & Exocytosis animations
Forces material out of cell
“cell-pooping”
membrane surrounding the material fuses with cell membrane
Cell changes shape – requires energy
EX: Hormones or wastes released from cell