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Cell Transport 7-3 Pgs. 182-189.

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Presentation on theme: "Cell Transport 7-3 Pgs. 182-189."— Presentation transcript:

1 Cell Transport 7-3 Pgs

2 Cell Membrane Cell membrane regulates what leaves and enters the cell.
It is a lipid bilayer with proteins embedded in the layer.

3 Phospholipids Phosphate head- polar “likes” water
Lipid tail- 2 fatty acids- non-polar- does not “like” water

4 Phospolipid Bilayer There are 2 types of proteins in the lipid bilayer
Integral Proteins- transport substances across membrane Peripheral Proteins- bind to the bilayer temporarily, perform various cellular processes.

5 Phospholipid Bilayer Cholesterol plays an important role in maintaining the integrity of the membrane. Keeps it firm and from becoming too permeable. Carbohydrates- Act as cell markers, allow cells to identify each other.

6 Cell Membrane Video

7 Diffusion All cells must exist in a liquid environment in order to survive. A solution is a mixture of two or more substances. Solute- substance dissolved into the solvent Solvent- substance solute dissolves into. Ex- iced tea mix is the solute, water is the solvent

8 Diffusion Particles are constantly moving in a solution.
Particles tend to move from an area of high concentration to an area of low concentration, this is called diffusion. Movement from high to low concentration is called the concentration gradient

9 Diffusion

10 Equilibrium Particles move from high to low conc. until they are the same throughout the system, this is called equilibrium

11 Diffusion Since particle movement is random, diffusion occurs across the membrane without the use of energy. Called Passive Diffusion

12 Osmosis Osmosis is the diffusion of water across a selectively permeable membrane.

13 Osmosis Water will move across a membrane until the concentrations of water and the solute are equal, this is an isotonic solution. Hypertonic solution- when there is more solute then water. concentrated Hypotonic solution- when there is more water then solute. dilute


15 Facilitated Diffusion
Proteins in the cell membrane allow some substances pass through easier then others. Still follows concentration gradient Ex- doorman at a club, lets some people in easier then others

16 Active Transport Sometimes particles have to move from low to high concentration, against the concentration gradient. This requires energy and is called active transport. Ex- swimming against the current of a river. Use proteins to carry particles across


18 Endocytosis and Exocytosis
Particles that are too large to pass through the membrane other ways Endocytosis- the cell membrane folds around an object and envelops it.

19 Endocytosis and exocytosis
2 types of endocytosis Phagocytosis- used for taking in food particles Pinocytosis- used for taking in liquids

20 Exocytosis Exocytosis is a process used to release substances from the cell. Vacuole fuses with the cell membrane and forces contents out of cell

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