Cell Membranes and Membrane Transport Ms. Bush/Ms. Cohen Cells Unit Biology Fall 2011

Cell Membrane Regulates what goes __________ Protection Support

Structure of Cell Membrane Lipid ___________ Proteins are embedded in the _______ _________ Cholesterol throughout Carbohydrate chains – Act as ___________

Phospholipids Building block of _______ _______ –Only has 2 _____________ –1 ____________ group Have –Hydrophilic heads –Hydrophobic tails

Fluid Mosaic Model The fluid mosaic model best describes the cell membrane as it has movement (fluidity) and is comprised of lipids, carbohydrates, cholesterol, and protein (mosaic). Bc Bc

Cell Wall Found in ______, algae, _______and many prokaryotes. Bacteria also have cell walls made of ______________ Outside the cell _________. Porous to allow water, oxygen, co2 thru Main function =

Measuring Concentration Solution - mixture of tow or more substances Concentration of solution is mass of solute in a given volume of solution 12 grams of salt in 3 Liters of water = 12 grams of salt in 6 Liters of water = Which one is more concentrated? _____________ A B

Diffusion across a membrane Equilibrium High concentration Low concentration

Osmosis Diffusion of ___________ through a ____________________.

Effects of Osmosis on Cells Conc of solutes same in & out Solution has more solute than the cell Solution has lower solute concentration than cell Water in and out! Water OUT! Water IN!

Facilitated Diffusion Is energy needed for this to happen?

Active Transport This transport is going AGAINST the gradient! What is needed to do this? ______________

Transport in Summary no energy requiredenergy required

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