Exam 2 ReviewKayotype AnalysisSpectral karyotyping- rainbow of chromosomes- Determines if there is a translocationo Part of one chrom detaches and attaches onto anotherChronic Myeloid Leukemia (Nowell and Hungerford)- density of cells much smaller- lethal and progressive disorder- increase in number of leukocytes (not alarming unless persists for a few months)- increase for 5 years without intervention then WBC are so high and organs are destroyed (secondary disoder)- ex. kidney failure because too many cells and proteins are released taking up too much space for other cells - early detection through Bone Marrow biopsyo cells taken → caused to proliferate → view under microscope → if chromosome 22 is shortened and reciprocal translocation with 9 and 22 = indicates CML- BCR from 22 attaches to ABL on 9o when BCR and ABL come together gene is always ono amino (NH3) | BCR|ABL| (COO-) carboxylico kinase indicates cells to proliferateo Transcribed translated into protein tells cells to proliferate cancer- Hard to treat b/c its genetico Treated with drug that inhibits ABL and cell proliferationo Bone marrowVisualization of Chromosomes1. Growing population of cells (proliferation)a. Replicating after treated with MPF- mitosis promoting factori. cyclin β – CDK1ii. staining pattern unique for chromosomes2. Treated w colchicine for 12-20 hrs -plant extract that inhibits microtubules (what pulls chroms apart in metaphase)3. Accumulate cells in metaphase4. Fix cells in Methanol-acetic acid5. Trympsin solution 10-15 min6. Stain with Giemsa (what codes for banding – a pattern that allows alignment of chroms) When looking under microscope many cells with many nuclei on slide chromosomes spread on surface cut chromosomes look at lengths, staining, #, to detect which chromosomeTransport Passive Transport- simple diffusiono equilibrium reached with timeo concentration of molecule inside and out are equal- facilitated diffusion (carrier-mediated) o protein embedded in membrane that speeds up processFacilitated Diffusiona) an aqueous channel, or Extend across lipid bilayer- Allow movements of specific molecules- Ex/ glycerol porino 6 helicies w 2 selectivity loopso Glycerol, straight chain sugars, urea, glycine (b/c 4 things go through it competition)o Has a polar pore and non polar exterior that interacts with membraneb) via a carrier. Aka transporters, bind the specific solute Undergo conformational changes to transfer across membrane When transporter is saturated (binding sites are occupied) rate of transport Vmax is highest Each transporter has a characteristic affinity for its solute (wont have random fattyacid trying to bind) Km (on concentration x axis) concentration at highest rate. (Km= ½ Vmax) Binding site can be blocked by inhibitors or glucose itself- Ex/ glucose translocator proteino 12 alpha helicieso GLUT 1,2,3,4,5o most tissues GLUT 1 and 3 → Km 1mM glucoseo most tissues getting glucose at 100% value of transport o muscles + adipose → GLUT 4 Km 5mMo liver + pancreas → GLUT 2 Km 15mMo GLUT1 → helices form wall of cylinder, hydrophobic pocket where ring structure of glucose is recognizedWhat are the molecular features of the glucose transporter subunit in facilitated diffusion?- 12 alpha helicies with amino and carboxylic ends on cystolic side (cytoplasm)- hydrophobic pocket, conformationally similar for ring structure of glucoseHow would you determine whether the transport of the amino acid glycine into red blood cells occurs by simple diffusion or by facilitated diffusion? If glycine were to be importedby facilitated diffusion, how could you determine whether or not another amino acid (such as methionine) moves into the cells by the same carrier?- Simple diffusion- linear, continuously flows in at constant speed- Facilitated diffusion- shows leveling off of glycine, doesn’t continuously flow in- Mix glycine and methionine together, they start diffusing through membrane, o but if they are using the same carrier they are competing to diffuse, and therate of diffusion would be slower, showing facilitatedo if they are moving in at the same rate they are using simple diffusion because there is no competitionChannel: glycerol uptake in E. coli- aqueous channel for specific mol- cell wall and plasma membrane arediffusive barrier- Why might a single mutation in E. coli result in simultaneous altered movements of glycerol, a four-carbon sugar, and urea through the cell’s membrane?- Glycerol porin transports : glycerol, straight chain sugars, urea, glycine- Theyre using the same channel, so if Ecoli has a mutation, it’s aqueous channel, or porin is altered and the uptake of glycerol, sugar, and urea is effected Example- mutations of gene coding for glycerol channel in mice makes mice obese because degradation of lipids involves movement of glycerol out of fat cells and if glycerol can't move mice become fat- glycerol, d-manitol, d-sorbitol, d-ribitol all can pass through channel because geometry of channelo TEST: mutating gene for glycerol channel and all molecules will be effected because none can pass through nowo TEST: competition, add glycine and rate of glycerol will be slower b/c of competitionAquaporin- proteins embedded in the cell membrane that regulate the flow of water, abundant in epithelial cells of kidney- 6 alpha helices (in green) form wall of cylinder, core provides channel, with 2 selectivity loops in cytoplasm and extracellular, which selects for the water- 28 KD- amino and carboxylic ends on cystolic sugar chain that goes out into extracellular spaceWhat is the mechanism responsible for the increased capacity of adipocytes to transport glucose from the blood in response to an elevation in the concentration of blood insulin? Give the details. Outline the study discussed in lecture that demonstrated the phenomenon using cultured adipocytes. High blood glucose, causes pancreas to secrete insulin – cell signaling molecule, causes fat cells (adipocytes) to take up more glucose, releases GLUT4 receptors that fuse w membranes to bring in more glucose fluorescent tag on GLUT4 w insulin moved everything outwards to membraneo no insulin, didn’t move to cell membraneActive Transport (ch 11 pg. 656)- Primary- ATP broken down to functiono electrogenic pump- voltage in cell will be more negative, voltage allows for more energy, ATPo J. Skou (1957) discovered Na+-K+ ATPase electrogenic pump =
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