BIO 105 1st Edition Lecture 5Outline of Last Lecture I. Cell TheoryII. Why are Cells so Small?III. Cell MembraneIV. Major Types of CellsV. Prokaryotic CellVI. Eukaryotic CellOutline of Current Lecture I. Membrane AttributesII. Diffusion and OsmosisIII. Cells in Solution (Tonicity)IV. Crossing the MembraneCurrent LectureMembrane Attributes1) Fluid Mosaic Modela) Mix of diverse proteinsb) Freely moving phospholipids2) Selctively Permeable Membranea) Choosy!b) Some molecules can pass. Some can’tDiffusion and OsmosisThese 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.1) Diffusiona) Movemnet of particles in a spaceb) Always from high to low!c) Molecules diffuse down to their concentration gradients2) Diffusion Across Membranea) Passive Transporti) Doesn’t require energyii) Uses diffusioniii) Molecules move down the gradient3) Osmosisa) Diffusion of Wateri) Water moves down to concentration gradient4) Moving Water into the Cella) Water is polarb) Cell membrane is nonpolarc) Water travels through aquaporins, proteins in the membrane that allow water to crossd) If a solute can’t cross, the water will use osmosis to reach equilibriumCells in Solution1) Tonicitya) Hypertonici) High concentration of solutes in the outer environmentb) Hypotonici) Low concentration of solutes in the outer environmentc) Isotonici) The outer an inner environments have the same concentration of solutes.Crossing the Membrane1) Simple Diffusion/ Passive Transporta) Hydrophobi moleculesb) Small molecueles (such as O2 and CO2)2) Facilitated Diffusion (Diffusion with help)a) Large moleculesb) Polar (charged) molecules: ionsc) Hydrophilic molecules (such as glucose)d) Molecules move down the gradiente) There’s no ATP(energy) needed3) Active Transporta) Molecules move up the gradientb) ATP (energy) is required4) Bulk Trasporta) Exocytosis: exports large molecules (such as proteins and sugars)b) Endocytosis: imports large moleculesc) Vesicles move these large molecules 5) Phagocytosis: particle’s movement6) Receptor Mediated Endocytosis: Just means it’s cargo
View Full Document
Unlocking...