PHIS 206 1st EditionLecture 2Outline of Last Lecture Cell StructureI. PhysiologyII. HistoryIII. HomeostasisOutline of Current Lecture I. Cell PhysiologyII. Organs― Communication Methods Required!III. FluidsIV. How Solutes BehaveV. Red Blood CellsVI. Historical Background: 17th CenturyVII. How Do Large Molecules Get Across?Current LectureI. Cell Physiology- General Physiology : “old” phrase Assumption: if you know one cell’s trick, then you know the others- We all carry a steady supply of red blood cells coming from 1 place Red blood cells: not much more than a bag of hemoglobin Easy to measure volume of red blood cells (cylinder, ruler, etc…)- Sea urchin eggs spherical (volume= know the diameter) 2 places to find them: Cape Cod and Bay of Maples- Nerve Cells A lot of similarities to a squid (1 nerve cell) Easy to handle Can change fluid conveniently Larvae of Fruit Fly: easy to see large nucleus and chromatin- Studying Cells Assumption: find an organism that is easy and study its cells (workable method) Evolution: once Nature figures out a way, process/mechanism is preservedThese 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. Negative: Is cell atypical to every organism?II. Organs― Communication Methods Required!- Pancreas: delivers digestive juices to small intestine Simultaneous process: continues to do while food enters the bodyIII. FluidsIntracellular (ICF): inside cells Extracellular (ECF): outside cells-LOW concentrations of Na+ -HIGH concentrations of K+-HIGH concentrations of Na+ (15-20 × greater)-LOW concentrations of K+*Conc. of Na+ and K+ in ICF and ECF are only equal in DEATH. IV. How Solutes Behave - simple diffusion: random motion of molecules caused by heat*When it becomes red, the chance of red dye molecules moving ↑ or ↓ is the same at equilibrium. - Diffusion rate is proportional to conc. of diffusion × area × Kelvin FIGG’S EQUATION viscosity × thickness × mol. size Not sensitive to temperature since temperature does not change much Slower than viscosity (flow) inverse relationship Membrane’s thickness affects diffusion rate inverse relationship Bigger molecule, slower diffusion Bigger membrane, faster diffusionV. Red Blood Cells- Diffusion by delivering oxygen from red blood cells to muscle cells FAST muscle cell capillary containing red blood cellSeparated by cell membrane:permeable to Na+ and K+-Probability that water molecules move to red dye = 0%-Probability that red dye moves out water = 100%-Area of red cell rel. to body ishuge-Temp. is constant-Mol. size of O2 is small-Thickness is small- Smaller objects tend to have larger surface areas Rate of consumption will increase so rate of O2 entering increases Automatically wind up w/ a nearly constant O2 concentration- Things that will diffuse: SolubleSmall (larger than glucose, smaller than sucrose)VI. Historical Background: 17th Century- Early model: Membranes must be layers of lipids- Water molecules could fit through the membrane’s pores if they were small VII. How Do Large Molecules Get Across?- Facilitated diffusion: proteins embedded in membranes can weakly bind certain molecules- Graph: Concentration Differences v. Diffusion Rate (x-axis v. y-axis) carrier proteins: the side that the molecules attaches has higher concentrations NO ENERGY for facilitated or simple diffusion Only concentration matters Something going downhill does not require an Energy inputAt same conc., saturated
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