BSC 114 1st Edition Lecture 11 Outline of Current Lecture Major Topics:- Permeability and transport of the lipid bilayer- Osmosis- Membrane Transport- Bulk TransportCurrent Lecture Lecture 11- Chapter 7: Membranes-A lot of traffic moves both ways across membranes.-Sugar, amino acids and nutrients enter cells and waste products leave.-Oxygen goes in and C02 goes out. –Small ions (Na, K, Ca, Cl) shuttle in both directions. Size and Charge - Channel Protein: passage way “tunnel.”-hydrophilic, welcome things with a charge-do not need energy simple transfusion or passivePassive Transport: requires no energy (like a bike going downhill)Active Transport: uses energy (bike going uphill)Diffusion: Spontaneous process (example: cool aid mixing by itself)Osmosis: the movement of water if a solute can’t pass membrane but water can, the water will diffuse to the area of higher solute concentration.Diffusion: molecules distribute themselvesHypertonic: the solute with a higher concentration of solutesHypotonic: lower amount of solutes***Water moves from less solute, to more solute.***Isotonic: solutions of equal amounts of solute concentration, inside and out. (Figure 7.12 Osmosis, in book)Osmoregulation: Contractile vacuole (paramecium). –Makes sure water concentration is balanced.--NOTE: Animal cells have no cell wall. Plant’s cells do have cell walls.Facilitated Diffusion: movement of molecules (up, over, down)-polar molecules and ions-no energy requiredChannels- hydrophilic on the inside of proteins. Carriers. Facilitated Always Gated.-Active Transport- (2 forms)1. ATP(energy input)-Co-transport (specifically transport protein) 2. AT, Con’t.- Sodium pumped out. Potassium pumped in. Pumps Na+ out and K+ in to cells.KNOW THE 6 STEPS (fig. 7.16)1. Cytoplasmic Na+ binds to sodium2. Na+ binding stimulates phosphorylation by ATP3. Phosphorylation causes protein to change shape4. K+ binds on extracellular side and triggers release of phosphate group5. Loss of phosphate restores original shape6. K+ is released and the cycle repeatsCo-Transport- movement of 1 solute down its concentration gradient provides energy to move another up its concentration gradient. (Example, “Sucrose transport video” on Black Board