Attempt History LATEST Attempt Time Attempt 1 59 minutes Score for this quiz: 47 out of 65 Submitted Oct 17 at 8:03pm This attempt took 59 minutes. Question 1 3 / 3 pts True or False: The nonpolar nature of water is an integral feature to its role as "the solvent of life." True Correct! False Question 2 5 / 5 pts Match the statement regarding organelles/organelle function with the appropriate organelle: Correct! Nucleus Correct! Mitochondrion Correct! Rough endoplasmic reticulum Correct! Golgi complex Correct! Endosome Question 3 0 / 3 pts Mark any/all statements that are TRUE regarding reactions and enzyme catalysis. You Answered The transition state of an enzyme-catalyzed reaction is destabilized in comparison to the transition state of the uncatalyzed reaction. The role of an enzyme in catalysis is to increase the difference in free-energy between the products and reactants (increase the G for the reaction). Correct Answer None of these is correct. You Answered The free-energy of a reaction ( G) determines the rate of reaction. In thermodynamics, the term "spontaneous" means that a reaction requires energy to proceed. Question 4 0 / 3 pts You squeeze some lemon juice into a glass of water. Lemon juice is a source of citric acid. What is the most likely pH of the water in the glass? 13 You Answered 7 Correct Answer 5 1 10 Question 5 0 / 3 pts For an enzyme that follows Michaelis-Menten kinetics, choose the best statement: Vmax can be attained as you add heat to the system. You Answered Vmax is attained at very high substrate concentrations. Correct Answer Vmax can be approached but never truly attained. Vmax is completely independent of enzyme concentration. Question 6 0 / 3 pts Mark any/all that apply to uncompetitive inhibition: None of these is correct. Correct Answer KM/Vmax are equal for both the inhibited and the uninhibited reaction. You Answered Inhibition can be overcome by the addition of more substrate. Correct! The inhibitor does not resemble the substrate. You Answered The inhibitor can bind to both enzyme alone AND enzyme that is bound by substrate. Question 7 3 / 3 pts Mark any/all that are allosteric regulators of oxygen binding to hemoglobin. Correct! CO2 Correct! 2,3-BPG Correct! H+ Question 8 3 / 3 pts Choose any/all amino acids that have a hydrophobic R group. Correct! Isoleucine (Ile) Asparagine (Asn) Correct! Valine (Val) Arginine (Arg) Lysine (Lys) Glutamine (Gln) Question 9 3 / 3 pts True or false: The reaction that forms a peptide bond results in the loss of a water molecule (otherwise known as a dehydration reaction). Correct! True False Question 10 3 / 3 pts Choose the best statement regarding the R groups of amino acids in an They are completely incompatible with helix formation. Correct! helix. They stick out from the axis of the helix. They are located in the interior of the helix. They participate in H-bonds that stabilizes the helix. Question 11 3 / 3 pts A protein with a known mass of 240 kDa is treated with -mercaptoethanol, a sulfhydryl reducing agent. When the resultant peptide mixture was analyzed by SDS PAGE, one protein band of 80 kDa was present. What is the most likely number of disulfide bonds that were present in the original structure of the protein? 1 4 Correct! 2 5 Question 12 3 / 3 pts Choose any/all that apply. Proteins can be purified on the basis of: Correct! Charge Correct! Size -Helix content All of these are correct. -Sheet content Correct! Solubility Question 13 3 / 3 pts JOKE QUESTION: What is a pirate's favorite amino acid? Correct! Arrrrrrrginine (this is the correct answer lol!) Pilagine Parrotine Plunderine Question 14 0 / 5 pts Consider a hypothetical enzyme that is COMPLETELY deactivated when a Valine (Val) residue buried in the core of the enzyme is mutated to Glutamate (Glu). In one or two sentences max, explain the MOST LIKELY reason for this occurrence. Your Answer: The most likely reason for this occurence could be as a result of induced fit whereby the substrate causes a conformational change in the enzyme. Val has a hydrophobic R group buried in the core of the enzyme -1 Glu has a charged hydrophilic R group that interacts with H2O -1 Introducing charge into the hydrophobic core of the enzyme destroys the tertiary structure, rendering it inactive -3 Question 15 4 / 4 pts Please answer this question to the best of your ability. I am not looking for any answer in particular. However, for full credit, you must answer completely and thoughtfully (ie-use constructive criticism...answers such as "Dr. Copp is the worst" do not help me improve and will not get full credit). Your feedback will help me improve the course, going forward through this quarter, FOR YOU! In addition, I may share some of your responses (anonymously) with my superiors to help them evaluate my performance. There are many resources available to help you learn the material. Examples include: 1) Powerpoint slides/presentations 2) Lecture Videos 3) Office Hours 4) E-mail/electronic correspondence 5) Homework problems and discussions Which of these have you found the most helpful? In which ways can I improve? Your Answer: I find the office hours helpful as it helps to focus one's attention on what is essential to learn towards the quizzes. It may be helpful to add more critical information to the PowerPoint slides. The homework problems are also helpful; however, they are not representative of the quizzes. Dr. Copp is very prompt with electronic correspondence and always willing to explain difficult concepts. Thank you for the feedback. Just so you are aware, I can point out the link between every quiz question and hw...some of the multiple choice selections are taken verbatim from hw problems. Question 16 14 / 15 pts This is the file upload question. mTOR is a cytoplasmic kinase that regulates cell division. Its misregulation can lead to cancer. The canonical mTOR inhibitor, rapamycin, is FDA approved as a cancer treatment. Rapamycin is an allosteric inhibitor that does not bind anywhere near the substrate binding site of the enzyme. A) What is the name of this type of inhibition? B) Sketch a REPRESENTATIVE double-reciprocal/Lineweaver-Burke plot that includes the enzyme kinetics for BOTH the uninhibited and inhibited reaction. Be sure to: 1) Make ABSOLUTELY clear which curve is your uninhibited reaction and which is your inhibited reaction. 2) Label the X and Y axes. 3) Indicate what the X- and Y-intercepts represent with regards to Michaelis-Menten kinetics. C) Can increasing the substrate concentration overcome this type of inhibition? Explain in a sentence or two. CamScanner 10-17-2022 21.17.pdf C) Looking for the inclusion of ANYTHING like “this mechanism lowers the amount of functional enzyme” in answer -1 Quiz Score: 47 out of 65
