Simple Diffusion

http://images.google.com/imgres?imgurl=http://www.esu7.org/~lweb/gifs/cells.jpg&imgrefurl=http://www.esu7.org/~lweb/Lakeview/science/sea.htm&usg=__WRoEbPFHEL_0_lRaf6ch87l7Vfg=&h=214&w=500&sz=15&hl=en&start=1&um=1&tbnid=HB_KYZJxlxHSHM:&tbnh=56&tbnw=130&prev=/images%3Fq%3Dred%2Bblood%2Bcells%2Bhypertonic%2Bsolution%26um%3D1%26hl%3Den%26sa%3DN

Simple Diffusion

Osmosis- movement of water towards high solute concentration

Describe each solution relative to the RBC.

http://ilovebacteria.com/Images/blood.jpg

In A, how would you describe the solution the cells are in? And in B?

Isotonic solution

(B) Lysed (C) Shriveled

(D) Flaccid (E) Turgid (F) Shriveled

Hypertonic solutionHypotonic solution

Plantcell

Animalcell

(A) Normal

Plasmamembrane

(plasmolyzed)

Active Transport

• Move solutes against concentration gradient, [L][H]

• Requires energy from ATP (adenosinetriphosphate)

• Example, sodium potassium pump, K+ in and Na+ out

Transportprotein

Solute

Solute binding1 Phosphorylation2 Transport3

Proteinchanges shape

Protein reversion4

Phosphatedetaches

Active Transport

Transport of Large Molecules Across Membranes

Cells rely on:• Exocytosis• Endocytosis

a. phagocytosisb. pinocytosisc. receptor-mediated endocytosis

Phagocytosis

EXTRACELLULARFLUID

Pseudopodium

CYTOPLASM

Foodvacuole

“Food” orother particle

Foodbeingingested

Pinocytosis

Plasmamembrane

Vesicle

Plasma membrane

Pinocytosis- material in droplet not regulated

Coatedvesicle

Coatedpit

Specificmolecule

Receptor-mediated endocytosis

Coat proteinReceptor

Coatedpit

Material boundto receptor proteins

Plasma membrane

*human cells use process to take in cholesterol from blood

Phagocytosis

EXTRACELLULARFLUID

Pseudopodium

CYTOPLASM

Foodvacuole

“Food” orother particle

Pinocytosis

Plasmamembrane

Vesicle

Coatedvesicle

Coatedpit

Specificmolecule

Receptor-mediated endocytosis

Coat proteinReceptor

Coatedpit

Material boundto receptor proteins

Plasma membrane

Foodbeingingested