BCMB 8020 Exam III April 1 2010 Name True False 1 2 point each 10 points total 1 Regarding bacteria both Gram positive and negative microbes utilize a Sec dependent transport system H pylori infection involves injection of a virulence factor into the host by a Type I secretion system approximately 33 of the population has suffered an H pylori infection approximately 50 of stomach cancers are associated with H pylori infection 2 Based on lecture and your reading of Protein translocation across the eukaryotic endoplasmic reticulum and bacterial plasma membranes by Rapoport the protein conducting channel is composed of a heterotetrameric complex i e 4 distinct subunits forms an hourglass shaped pore with the constriction near the ribosome attachment site is self sufficient for mediating transport of polypeptides i e extra factors energy is not needed interacts with signal sequences that have inserted as a loop N terminus toward the cytosol 3 Regarding lipid biosynthesis acetyl CoA is a common precursor to both fatty acid and isoprenoid lipids ATP is used during the synthesis of both fatty acid and isoprenoid lipids NADPH is used during the synthesis of both fatty acid and isoprenoid lipids products with an even number of carbons are generated by the fatty acid biosynthetic pathway 4 Based on your reading of Lipid Rafts as a Membrane Organizing Principle by Lingwood et al cholesterol preferentially associates with the liquid ordered Lo phase in purified lipid systems the liquid disordered Ld phase has a thicker width than the Lo phase in purified lipid systems the terms Lo and Ld are terms that apply to biological membranes the width of lipid rafts in biological membranes is typically in the micrometer range 5 The phosphorylation event associated with transport by the P Type Ca2 pump occurs on a Ser residue is mediated by GTP induces structural rearrangements of the transporter contributes to formation of a desolvation ring Multiple Choice 2 points each 26 points total one correct answer per question 6 A friend of yours is employed as a pharmaceutical researcher and has just developed a new FDAapproved drug What is the probability that the target of the drug is a membrane protein A 10 B 25 C 50 D 75 7 Based on the reporters used for the FRAP movies shown in class which membrane has a more dynamic character A endoplasmic reticulum B Golgi C plasma membrane D nuclear membrane BCMB 8020 Exam III Name 8 Which of the following locations does not necessarily require a polypeptide based import signal for transport of newly synthesized small proteins 5 kDa A endoplasmic reticulum B nucleus C periplasmic space of Gram negative bacteria D peroxisome 9 Together the membranes of the endoplasmic reticulum and mitochondrial represent approximately what percent of total membrane in a typical eukaryotic cell A 25 B 33 C 67 D 90 10 If you want to radiolabel glycerophosphatidylcholine PC which of the following would you use Assume that you have phosphatidic acid unmodified head groups and other necessary reagents enzymes as starting reagents A 32P ATP B 32P CTP C 32P GTP D none of the above 11 The ENTH domain binds A calcium B diacylglycerol C phosphoinositide lipids D C termini of certain proteins 12 Based on your research of the topic which of the following tissue has the highest concentration of docosahexaenoic acid DHA A blood cells B brain C liver D muscle 13 A key step in hedgehog biosynthesis looks much like which of the following protease mechanisms A aspartic acid B cysteine C serine D metallo 14 With respect to the serine protease mechanism the proton associated with the nucleophilic hydroxyl is transferred to A a histidine and eventually returned to the serine B the C terminal portion of the product C the N terminal portion of the product D water 2 BCMB 8020 Exam III Name 15 Which of the following types of lipid modified proteins has a free unmodified carboxyl terminus A cholesterol modified B GPI linked C isoprenylated D S acylated 16 Which of the following has to be modified by the methionine aminopeptidase A PKA B Ras C SNAP 25 D Hedgehog 17 P type transporters share a common architecture with most of their differences confined to which domain A actuator B hinge C phosphorylation D transmembrane 18 Which of the following is not a site from which ABC type transporters access their substrates A cytosolic environment B extracellular environment C inner leaflet of plasma membrane D outer leaflet of plasma membrane Short Answer These can be answered using keywords lists diagrams and or 1 2 sentences 1 4 points each 36 points total 19 You have radiolabeled versions of each amino acid at your disposal Which amino acid would you use to radiolabel all sphingolipids 1 point 20 Using your knowledge of FRET and the graphic below provide an identity for each curve A D using combinations of these terms acceptor donor emission excitement 4 points A B C D 21 What are the distinct experimental approaches described in class as being used to establish juxtaposition of extracellular GPI proteins and intracellular Src family kinases across from each other at the plasma membrane 2 points 3 BCMB 8020 Exam III Name 22 Using the stick figure method draw the chemical structure of a naturally occurring 16 2 6 11 fatty acid 4 points 23 What is a major molecular protein target of cocaine AND how does it affect the function of its target Specific mechanistic information on the interaction is not required for the answer 2 points 24 A seal holds the ribosome and protein translocation channel together What are the key features of the mRNA needed for setting up the quenching experiment described in class lecture that was used to assess the tightness of the seal 3 points 25 Sphingomyelin synthesis directly depends on which glycerophospholipid 1 point 26 Which amino acid aids in the function of the peptide interaction domains of Calmodulin and SRP 1 point 27 From the lecture material provide the names of three distinct types of proteins that undergo N terminal myristoylation 3 points 4 BCMB 8020 Exam III Name 28 Circle the protonation state expected at neutral pH for each of the amino acids shown in the table below 3 points 29 Which of the four standard protease classes A utilize water as part of their mechanisms of action 2 points B form acylated intermediates as part of their mechanism 2 points 30 Among PMSF TPCK or TLCK which A makes for the better non selective specific inhibitor of serine proteases 1 point B