41) Spacing between residues (every 100degrees), right-handed twist. Side chainswith the same charge are positioned rightnext to one another; also, the helix dipoleisn’t stabilized, so this is unlikely to form analpha helix.42) Need to show where beta sheets, alphahelices and left-handed alpha helices resideon this plot. The L-Ile residues would takeup a smaller subset of Ramachandranspace, because of steric hindrance fromtheir bulkier side chains.43) Higher [H+] decreases oxygen bindingbecause the His HC3 side chain isprotonated at high [H+] - and this causesthe His side chain to acquire a positivecharge. The positively charged His HC3forms an ionic interaction with thenegatively charged Asp FG1. Thisinteraction stabilizes the non-oxygenbinding, T-state of hemoglobin.44) The antigen binding site is formed fromhypervariable loops extending from twodifferent Ig domains, one from the lightchain and one from the heavy chain. Theanswer should have a diagram showing thestructure of an Ig domain (two beta sheetspacked tightly against each other), andshow how the loops from the two Igdomains come together to form a singlebinding surface.45) Bound peptides are 13-17 a.a. in length.The termini are not bound.The backbone of the peptide H-bonds withthe MHC class II receptor.Specificity pockets (2 or 3) interact withparticular side chains of the peptide.Fig.11-4 B and TFig. 6-16LehnFig. 6-19LehnFig. 11-6 B and TFig. 6-18LehnFig. 11-5 B and TFig. 6-21LehnFig. 6-21LehnFig. 6-21LehnFig. 11-5 B and TFig. 6-21LehnFig. 6-21LehnFig. 6-21LehnFig. 6-21 LehnFig. 11-5 B and TFig. 11-6 B and TSite-directed mutagenesis of Subtilisin(another serine protease)Fig. 6-21LehnFig. 11-11 B and TElastin, the substrate for ElastaseLE 48-17Postsynaptic cellPresynaptic cellSynaptic vesiclescontainingneurotransmitterPresynaptic membraneVoltage-gatedCa2+ channelCa2+Postsynaptic membranePostsynaptic membraneNeuro-transmitterLigand-gatedion channelNa+K+Ligand-gatedion channelsSynaptic cleftLE 42-17Endothelium ofvessel is damaged,exposing connectivetissue; platelets adherePlatelets form a plug Seal is reinforced by a clot of fibrinCollagen fibersPlatelet plugPlatelet releases chemicalsthat make nearby platelets stickyClotting factors from:PlateletsDamaged cellsPlasma (factors include calcium, vitamin K)Prothrombin ThrombinFibrinogen FibrinFibrin clot Red blood cell5 µmFig. 6-18LehnFig. 6-18 LehnFig. 6-18LehnFig. 11-7 B and TFig. 6-26LehnFig. 12-15 LehnFig.
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