QBM Exam 1 Questions And Answers With Complete Solutions 2024

QBM Exam 1 Questions And Answers With Complete Solutions 2024 Which of the following refers to manipulating a piece of DNA and putting it into a plasmid for the purposes of gene studies, protein expression, and gene therapy? - answerRecombinant DNA technology What type of bond is found in a protein that connects individual amino acids? - answerpeptide Employers must inform employees and train them in the safe handling of potentially harmful chemicals. This is required by - answerOSHA Research labs that handle pathogenic organisms for which there is no vaccine that can cause diseases which are generally untreatable and fatal are assigned a rating of - answerBSL-4 Which type of gloves offer the least amount of protection from chemical/biological hazards? - answerPlastic Absorbance and transmittance are - answerlogarithmically proportional Absorbance and concentration are - answerdirectly proportional Colorimetry is used to make samples detectable in the _____ spectrum. - answervisible A type of centrifugation used in the lab to rapidly collect samples in 1.5 ml tubes is - answersmall bench top centrifugation With regards to potential destructive ability, which type of centrifuge is most dangerous and must be balanced within 0.1g? - answerUltracentrifuge When using a centrifuge to spin down a sample the pellet is considered the ___ fraction and the supernatant is considered the ____ fraction. - answerinsoluble; soluble If Meselson and Stahl had observed the following pattern they would have concluded that DNA replication was - answerconservative You have a 1.5 ml tube of frozen enzyme. Upon removing it from the freezer you should thaw it and spin it down briefly in a centrifuge. What is the purpose of this? - answerTo remove any liquid from inside the cap Which of the following is considered proper technique when handling a micropipette? - answerHolding the micropipette consistently vertical Spectroscopy refers to the separation of light into its wavelengths. - answerTrue When using a pipette, the greatest accuracy is achieved by - answerholding the pipette perfectly vertical Why are polypropylene bottles generally preferred in a research lab? - answerThey are more resistant to harsh chemicals Which of the following is FALSE about the image below? - answer"E.C." indicates that this pathway is from Escheichia coli. You are studying vinculin and myosin, and have two separate solutions as noted below: 1 L vinculin (approx 1000 amino acids) 1 L myosin (approx 2000 amino acids) Each samples has 10^23 copies of each protein per L. Which of the following is TRUE? - answerBoth proteins have the same molarity. Which of the following assays is measured at 340 nm? - answerCDNB Enzyme Assay Using the standard curve below, what is the concentration of a sample that gives an absorbance of 0.5 when 4 microliters of sample are assayed? - answer20 mg/ml What would you expect absorbance of a sample to be if it had a transmittance of 71.28% - answer0.147 A DNA sample with an A_260 of 1.92 and an A_280 of 1.35 is sufficiently pure. - answerFalse What region of an enzyme is often found to be highly conserved at the amino acid level across different species? - answerActive site Which of the following is correct regarding enzymes? - answerEnzymes can increase the rate of a reaction, but do not shift the equilibrium of a reation. Which wavelength would you use to measure protein concentration directly (without any chromagenic assay)? - answer280 Alligning the tertiary structures of chymotrypsin and subtilisin illustrates - answerconvergent evolution How would you prepare 25 ml of a 200 mM solution of HEPES (M_w = 238g/mol) pH 7.5? - answerAdd 1.19 grams HEPES to approx 20 ml of water, pH to 7.5, bring up to 25 ml. 75 M is equivalent to - answer75 moles per liter