UNE BIOCHEM|CHEM 1005 Unit 1 Exam|complete Solution Guide.

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BIOCHEM Unit 1 Exam Question 1 There is a mutation in the insulin receptor substrate that makes it unable to bind the phosphorylated insulin receptor. Which of the following will occur as a result o ... f this deficiency? Question 2 When glucagon binds its receptor there is an increase in the second messenger, cAMP. cAMP is synthesized by which of the following enzymes? Question 3 When insulin binds its receptor, which of the following proteins will become activated? Question 4 Which of the following is an example of a molecule or compound that can move across a membrane through simple diffusion? Question 5 Monocytes are unique cells that secrete the cytokine, interleukin-1. Once released, this cytokine will bind a receptor on the outside of the monocyte and regulate its response. In this situation, Interleukin-1 is best described as which of the following? Question 6 The concentration of an enzyme will impact the rate of an overall reaction. Which of the following will lead to an overall decrease in enzyme concentration? Question 7 When an enzyme is present in the R-conformation it usually binds which of the following with the greatest affinity? Question 8 The Lineweaver - Burk plot above illustrates the kinetics of a reaction with and without the addition of an inhibitor. Which of the following statements is consistent with this graph? Question 9 With respect to Michaelis-Menten kinetics, the addition of a noncompetitive inhibitor to a reaction would result in which of the following? Question 10 What is the [H+] concentration in a 0.001 M = 10-3 M solution of NaOH. (10-14 = [H+] [OH-]) Calculate the [OH] OR [H+] concentration if given the molarity of a solution. Question 11 The affinity for DNA and histones within a chromosome can be increased by which of the following histone modifications? Question 12 Which of the following enzymes or polymerases is responsible for the addition of the RNA primer to initiate DNA replication? Question 13 Which of the following enzymes is correctly paired with its allosteric inhibitor? Question 14 The ribonucleotide reductase is regulated at both an activity site and a substrate specificity site. Which of the following compounds must always be bound to the activity site for the enzyme to be active? Question 15 Allopurinol is an inhibitor of xanthine oxidase. Addition of this compound will result in a decrease in which of the following compounds? Explain the purine salvage pathway, specifically the reaction catalyzed by hypoxanthine-guanine phosphoribosyltransferase (HGPRT) (Figure 41.10) Question 16 You are counseling a family with regards to myotonic dystrophy which is an autosomaldominant disorder. One of the individual’s is affected by this disorder (genotype Rr) while the other is not. What is the likelihood that their child will not be impacted by myotonic dystrophy? Compare and contrast autosomal, sex-linked, dominant and recessive inheritance patterns Question 17 A deficiency in cystathionine β-synthase (transsulfuration pathway) can decrease synthesis of which of the following amino acids? Determine if a deficiency in a pathway will lead to an amino acid becoming essential See figure 11.17 Question 18 You are counseling a family with regards to Maple syrup urine disease (MSUD). The couple you are speaking with lets you know that they know their individual genotypes. The female is Rr while the male is RR. What is the likelihood that their child will be a carrier for MSUD? Compare and contrast autosomal, sex-linked, dominant and recessive inheritance patterns Determine the percent likelihood of a disease presentation given the inheritance pattern of the disorder Determine the possible genotype(s) of individuals if given their parents genotypes Question 19 Which of the following cofactors or vitamins is required for the conversion of homocysteine to cysteine? Question 20 A 2-year-old boy is recently diagnosed with red-green color blindness which is an X-linked recessive disorder. Which of the following represents the correct genotypes of this individual’s parents with respect to red-green color blindness? (X - wild type; X' recessive allele; R wild type autosomal allele; r recessive autosomal allele and Y chromosome) Question 21 DNA and histone associations can be modified by histone acetylation and deacetylation. This is an example of gene regulation at which level? Describe and give examples of eukaryotic gene regulation at the 4 levels: DNA, transcription, post transcription, translation and post translation (review Module 1 modifications to amino acids; examples are given in both the text and the guide posted for the module) Question 22 Use the figure above to answer this question. The schematic above illustrates a genomic sequence of two different alleles of the same gene. In the mutant allele there is a restriction fragment length polymorphism that adds an XhoI site. A Southern blot with a probe (denoted as XXXX in the figure) to DNA isolated from an individual who has both a mutant and a normal allele would produce which of the following results? Describe the utility of Western, Northern and Southern blots Define restriction enzyme and describe their utility in recombinant technology. Define the term 'probe' (Figure 17.3) Question 23 A mutation occurs in the GRE (glucocorticoid response element). This mutation makes the GRE unrecognizable by the receptor/ligand complex. What impact would this have on the transcription of the gene downstream of this element? Compare missense, nonsense, silent and insertion/ deletion mutations Compare intracellular vs extracellular signaling molecules Describe how transcriptional defects may result in changes to the translated protein product. Question 24 In the absence of iron, the iron response element binding protein (IRE – BP) binds the mRNA encoding for ferritin and inhibits protein translation. This type of gene regulation is best described as: Describe and give examples of eukaryotic gene regulation at the 4 levels: DNA, transcription, post transcription and translation Relate how levels of iron can modulate the transcription and translation of different protein products Question 25 A mutation that activates the kinase domain of a protein will result in: Question 26 Which of the following best describes the process during protein translation when the amino acid attached to the tRNA in the P site is transferred to the tRNA in the A site? Summarize the three steps of translation: initiation, elongation, and termination. Question 27 During protein translation, (after the initiation complex is formed), the addition of each amino acid to the growing polypeptide chain involves aminoacyl-tRNAs binding to which site on the ribosome? Summarize the three steps of translation: initiation, elongation, and termination. Identify the A, P and E sites within the rRNA and how these are used to synthesize a polypeptide strand Question 28 From the list below, please select all of the necessary events in pre-mRNA processing. 1. Addition of 3' amino acid attachment site 2. Addition of a 3' Poly A tail 3. Addition of a 5' cap 4. Splicing Describe the process of pre mRNA maturation including: the addition of the 5' cap, poly A tail and splicing. Question 29 Sickle cell is caused by a single point mutation that changes a glutamic acid to a valine. This type of mutation is best categorized as which of the following? Question 30 Which of the following genetic elements is within the transcribed region of a gene? [Show More]

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