Cell Transport

The cell membrane lets thing in and out of the cell Carbohydrates Cholesterol Protein Channel Cytoskeleton Phospholipids

The cell membrane is selectively permeable This means: it selects what can come into the cell “Semipermeable” outside cell inside cell aa sugar H2O NH3 salt lipid

Remember... Phosphate group head Fatty acid tails hydrophilic (likes water) Fatty acid tails hydrophobic (hates water) Arranged as a bilayer (bi = 2)

cell needs materials in & products or waste out Cell membrane is the boundary between inside & outside… separates cell from its environment  Can it be an impenetrable boundary? IN food carbohydrates sugars, proteins amino acids lipids salts, O2, H2O OUT waste ammonia salts CO2 H2O products OUT IN cell needs materials in & products or waste out

How do things get through the cell membrane? Passive Transport Diffusion Osmosis Facilitated Diffusion Active Transport

Diffusion Movement of solutes from high to low concentration No energy is needed SOLUTE MEMBRANE

WATCH The ink will diffuse in the water

Facilitated Diffusion Facilitated Diffusion: Molecules need a protein channel to pass through the cell membrane, no ATP needed Protein Channel

Facilitated Diffusion Protein channel allows specific molecules to pass Like the bouncer of a club! No energy is needed facilitated = with help high low “The Bouncer”

Osmosis Osmosis: the diffusion of water through a cell membrane

Concentration of water Direction of osmosis is determined by comparing total solute concentrations Hypertonic - more solute, less water Hypotonic - less solute, more water Isotonic - equal solute, equal water

Cell survival depends on balancing water uptake & loss

Active Transport Active Transport: Molecules need a protein pump to get into cell Uses Energy = Goes from low to high= UP the concentration gradient low high ATP ATP “The Doorman”

Endocytosis Endocytosis: taking things into the cell in vesicles Examples: Phagocytosis and Pinocytosis phagocytosis pinocytosis

How do larger molecules get in and out of the cell? endocytosis phagocytosis = “cellular eating” pinocytosis = “cellular drinking” exocytosis

Exocytosis Exocytosis: molecules exit the cell in vesicles

Watch & Try http://www.classzone.com/cz/books/bio _07/get_chapter_group.htm?cin=2&rg= animated_biology&at=animated_biolog y&var=animated_biology

Work on cell transport worksheet Review Work on cell transport worksheet