The Cell Membrane Osmosis and Diffusion
The Cell MembraneOsmosis and Diffusion
The Plasma (Cell) Membrane
- Flexible boundary- Allow entry and exit of
materials- Surface markers- Selectively permeable/semi-
permeable - Phospholipids- Fluid mosaic model
Channel Protein
Cell
Membrane
Lipid
Outside of Cell
Inside of Cell
Marker Protein
ReceptorProtein
Carbohydrate chain
Cells move substances through the cell membrane
by a process called transport
Two Types of Transport:
Passive Transport
Active Transport
What is Passive Transport?
Requires no energy from cell.
Molecules move from high concentration to
low concentration.
Molecules move with the concentration gradient.
What’s happening?
How would diffusion happen in a cell?
Osmosis is a type of diffusion
Cell Membrane
HELP WANTED!
I’m a Channel, I can help!
Explain what is happening
Cellular Transport and Osmosis
- Maintaining homeostasis/equilibrium
- Hypertonic solution – low water- Hypotonic solution – high water,
lyses- Isotonic solution – equal solutions
What would happen to the animal cells in each beaker?
100% Distilled Water
80% H2O
70% Water30% Dissolved
Substances
80% H2O
80% Water20% Dissolved
Substances
80% H2O
Which way did the water move?
100% Distilled Water
80% H2O
Why did the cell get so big?
Which way did the water move?
80% Water20% Dissolved
Substances
80% H2O
Why did the cell stay the same
size?
Which way did the water move?
70% Water30% Dissolved
Substances
80% H2O
Why did the cell get so small?
How is Active Transport different?
1. Active transport requires energy.
2. Molecules move from low concentration to high concentration
3. Molecules move against concentration gradient.
Which way would the solute be moving if this were active
transport?
90% Water
80% H2O
Why would it move that direction?
Types of Transport
- Passive transport- Diffusion – molecules from high to low- http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/
animation__how_diffusion_works.html
- Osmosis – water from high to low- http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/
animation__how_osmosis_works.html
- Active transport- http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/
animation__how_facilitated_diffusion_works.html
- Endocytosis – taking in- Phagocytosis – solids- http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/
animation__phagocytosis.html
- Pinocytosis - liquids- Exocytosis
- removal