BB 350 Practice Exam Name _____________ ID #__________ Friday, June 27, 3174, Noon General Instructions for Students: This is a 50 minute exam and it is worth 100 points total. Read the instructions for each question carefully. If you do not understand the instructions for a question or what is being asked in a question, raise your hand. Be careful how you mark your exam. If graders are uncertain about how any question is answered, it will automatically be marked incorrect. Do not spend too much time on any one question. Scores Section I (12 points) ________________ Section II (36 points) ________________ Section III (52 points) ________________ Total ________________ Important items A. The logarithm of a number greater than one is a positive number. B. The logarithm of a number less than one is a negative number C. For any number X (except X=0), ln (X) = -ln(1/X) [or log(x) = -log(1/x)] D. pH = pKa + log {[Salt]/[Acid]} E. pH = -log[H+] , pOH = -log[OH-], pKa = -Log[Ka], pH + pOH = 14 BB 350 practice exam, Page 1 Section I: The statements in this section can be completed by any of the lettered responses following it. Each statement may have more than one answer that is correct, one answer that is correct, or no answers that are correct. Students should clearly circle only those responses that complete the sentence to make a correct statement. Points will be awarded for each circled response that makes a correct statement and for each uncircled response that makes an incorrect statement. For example, the practice question below has three correct answers (b,c,d). You would receive eight points if you circled ‘b’,’c’, and ‘d’. You would receive two points if you circled ‘a’ and ‘b’. You would receive no points if you circled only ‘a’. If we have uncertainty about whether or not an answer is marked, it will automatically be counted as a wrongly answered question. Be clear in your markings. Practice question #A: Oregon State University A. is a factory in Portland B. is located in Corvallis, Oregon C. has a mascot named Benny Beaver D. has students from all over the world. 1. With respect to cells and their organelles, A. eukaryotes have a nucleus B. bacteria have a nucleus C. mitochondria have their own DNA D. there are no single cell eukaryotes 2. With respect to amino acids, A. all of them have a pI B. all of them differ in their R groups C. glycine is the only one lacking an amine group D. all of them have no charge at pH 7 3. With respect to protein structure A. the secondary structure refers to how two subunits interact B. folding is an example of tertiary structure C. no single subunit proteins have quaternary structure D. the primary sequence has the least effect on protein structure Section II: 1. Each sentence below in this section is missing a word or short phrase to complete it. Fill in the blank as appropriate to complete the sentence with a correct statement. Each correctly filled in blank below will be awarded three points. You MUST be precise in your definitions. BB 350 practice exam, Page 2 1. What causes peptide bonds to behave like a double bond? ________________ 2. The blood pH of your best friend suddenly rises. What happens to the concentration of oxygen in your best friend’s tissues? ________________ 3. Which amino acid is involved in forming the strongest bonds stabilizing tertiary structure? ________________ 4. What is the relationship between the pOH of a solution and the concentration of protons in it? ________________ 5. What type of chromatography relies on a negative charged bead to bind to positively charged proteins (answer must be specific)? ________________ 6. How is the Induced Fit model of catalysis described in one sentence? ________________ 7. Define the term ‘substrate’ ________________ 8. What type of chromatography uses a separation technique where the largest molecules move the fastest? ________________ 9. What protein is strengthened by vitamin C? ________________ 10. Relative to the last question, name an amino acid involved in the process _______________________ 11. What does the term ‘denatured’ mean with respect to protein structure? ________________ BB 350 practice exam, Page 3 12. How much time after exams are returned do students have to get corrections in? ________________ BB 350 practice exam, Page 4 Section 3 – Problems/Long Answer 1. Fetal hemoglobin differs from adult hemoglobin structurally and in how it binds to molecules. Describe the structural differences and the different ways it binds molecules compared to adult hemoglobin (12 points) 2. Name all of the forces described in class that stabilize protein secondary, tertiary, and quaternary structure. All you need to provide is a list of forces. (12 points) 3. A new amino acid (Ahernium) is discovered that has an R group with two amino groups and carboxyl group. The pKa values are as follows: Alpha carboxyl = 2.0 Alpha amino = 8 R-group amino #1 = 11 BB 350 practice exam, Page 5 R-group carboxyl #1 = 3.5 R-group carboxyl #2 = 5.5 Given the information above what would you expect would be the pI of Ahernium? Show your calculations and your reasoning(12 points) 4. For the following problem, ORGANIZE and LABEL your calculations clearly. No partial credit will be given without clearly labeled calculations. You do NOT have to enter the numbers into a calculator. You simply need to show the last step before punching it in. 1. 800 ml of a 1M buffer (pKa = 5.0) is at its maximum buffering capacity. 0.2 moles of NaOH is added followed by 0.3 moles of salt. a. Write an equation for the pH of the resulting solution. (6 points) b. How much HCl would you have to add to return the solution to its maximum buffering capacity? (explain your logic – required for credit) (10 points) BB 350 practice exam, Page 6