BOLOGY 107 Lecture 10Outline of Last Lecture I. Organellesa. Bulk Transportb. Plasma MembraneOutline of Current Lecture II. Plasma Membranea. Permeability b. Diffusionc. Transportd. Endocytosis e. Intercellular junctionsCurrent LecturePlasma Membrane1) Permeability a) Selectively permeable i) Small, non-polar, or uncharged molecules pass easyii) Large, hydrophilic molecules do not2) Diffusion a) Random movement of molecules from high concentration to low concentration until equilibrium is reachedb) Osmosisi) Water specific diffusionii) Based on molecule concentrations in water with a selective membranec) Tonicity i) Ability of surrounding solution to gain or lose water(1) Hypotonic- less solute in cell, surroundings gain water(2) Isotonic- same concentration in cell and surroundings, no net flow(3) Hypertonic- more solutes in cell, surrounding lose waterii) Cell conditions(1) Animal(a) Hypertonic- shriveled, isotonic- normal, hypotonic- burst(2) Plant(a) Hypertonic- plasmolyzed, isotonic- flaccid, hypotonic- turgid (normal)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.3) Transport a) Passive: diffusion, no energy used b) Facilitated: passive through a protein, no energy usedc) Active: against the gradient, needs ATP4) Endocytosis a) Phagocytosis i) Extends parts of membrane, pseudopodia, to engulf particle ii) Creates a food vacuoleb) Pinocytosis i) Invagination when in nutrient rich areaii) Creates vacuole with same contents around the celliii) Non-specificc) Receptor-mediated cytosisi) Binding of receptors to send signal to create vesicle ii) Form protein coated vesicleiii) Can be hijacked by viruses, used in negative feedback5) Intercellular junctions a) Tight- links cells with a fluid tight barrierb) Desmosomes- structural attachment linking intercellular matrixc) Gap junctions- connection allowing flow (animal cells only)d) Plasmodesmata- connection allowing flow (plant cells
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