H 2 C NH 3 CH 2 CHCOO

Transcription

1 Make sure You have FIVE Different 110 April 29, 2009 Pages Including this over Page. over Page You may pick up your graded exam after 120 minutes Final Exam 5/4/09 until 12/01/09 DETA TIS SEET AND USE AS A VER SEET/SRAT SEET. KEEP YUR WRK VERED! BRIEFLY LK VER TE EXAM FIRST. SEE ALL TE INFRMATIN TAT IS PRVIDED FR YUR USE. YU MAY USE INFRMATIN PRVIDED ANYWERE N TIS EXAM. ALLATE YUR TIME. ANSWER EA F TE QUESTINS IN TE SPAE PRVIDED glyceraldehyde dihydroxyacetone 2 erythrose 2 A a B b 2 2 ( 2 ) n' 3 P ( 2 ) n N( 3 ) 3 2 c 3 ( 2 ) 12 E g 3 N R 2 P 2 2 N( 3 ) 3 F l 2 3 d 3 e f D threose 2 2 ribose ( 2 ) 16 3 ( 2 ) 14 3 ( 2 ) 16 3 ( 2 ) n 3 ( 2 ) n' 3 P j i N 3 2 k h N fructose Serene (Ser) N 3 N 3 2 Tyrosine (Tyr) 2 2 galactose N 3 NN 2 N Arginine (Arg) 2 N 3 N N 2 Glutamine (Gln) 2 Aspartic Acid (Asp) N Proline (Pro) 2 glucose ysteine (ys) N 3 Glycine (Gly) N 3 2 S N 3 N Isoleucine (Ile) 3 Threonine (Thr)

2 Name (1 pts) 110 April 29, minutes T A Page 1 of 4 Final Exam 22 pts 01) omplete each of the following with the correct word or phrase: With few exceptions an enzyme is principally composed of A cofactor is. A coenzyme is. The following are enzyme names, what do these enzymes do? Transferase Lyase Ligase What specifically does Lactate dehydrogenase enzyme do? it is classified as a(n). Explain why enzymes work best over very narrow ranges of p and temperature:. Explain briefly the lock & key mechanism of enzyme specificity:. Explain briefly how the induced fit model differs?. Draw and label a graph showing the different responses of an enzyme as the concentration of substrate increases when a) the enzyme is not under the influence of an inhibitor; b) under the influence of a competitive inhibitor, and c) when it is under the influence of a non-competitive (allosteric) inhibitor. Explain briefly how a competitive enzyme inhibitor works: Explain briefly how an allosteric enzyme regulator works:

3 Name 110 April 29, 2009 T A PAGE 2 of 4 Final Exam 24 pts02) n the cover page, lipid molecules labeled A-F have various functional groups or identifiable structures indicated by the lower case letters: a-l; name them (1 pt ea). Place the uppercase letter(s) from the cover sheet for the proper choices in the spaces provided: Which lipid is a bile salt?. Which lipid is a triacylglycerol?. What physical phase will this lipid likely have at 25E?. Which phospholipid is a sphingomyelin?. Which have choline residues?. Which are phosphatides?. Which phospholipid is a cephalin?. Which is a hormone regulating Na /K levels?. Which is a plasmalogen?. Which lipids have aminoacid residues?. 23 pts 03) Using the first-three-letter labels for aminoacids from the coversheet answer the following questions. (1 pt ea) a) Which of the amino acids have a phenol side group? b) Which of the amino acids will have a pi < 5? c) Which of the amino acids will have a pi > 7? d) Which non-polar amino acid has more than one tetrahedral stereocenter? which has none e) The primary structure of a protein is f) What two common secondary structures do proteins take? and. g) Describe the specific interactions which stabilize the secondary structure in each case (same order) (2 pts) and. (2 pts) h) Name the covalent link that stabilizes the tertiary structure of proteins: Write a general chemical equation illustrating the formation of this link using the amino acid(s) involved. (2 pts): i) Name the ionic link that stabilizes the tertiary structure of proteins: Which two amino acids from the cover sheet would pair in this way?. j) The quaternary structure of a protein is k) Draw the structure of the tetrapeptide: Pro-ys-Ile-Tyr at its isoelectric point (with Pro being the N-terminus) (3 pts): l) Is the tetrapeptide in j) hydrophilic hydrophobic (circle)? Why?.

4 Name 110 April 29, 2009 T A PAGE 3 of 4 Final Exam 23 pts 04) Using the Fischer carbohydrate structures and the aworth templates on the cover sheet, draw aworth structures for A) β-galactose and B) α-glucose and ) α-lactose, a disaccharide which is composed of glucose and galactose and occurs principally in milk. Place asterisks (*) at the anomeric centers in each structure. Explain why lactose is not digestible by some adults?. A) B) ) Lactose is a Reducing Non-reducing (circle) sugar? Explain why?. Using the aworth template on the coversheet draw the aworth representations for A) β-ribose B) β-2-deoxyribose. Place an asterisk (*) at each anomeric center. A) B) Explain briefly the significance of the transformation of A) into B). l) Determine the R/S system designation for each of the two stereocenters of erythrose (shown on the coversheet). m) All natural sugars have the R S (ircle) configuration at the penultimate stereocenter.

5 Name 110 April 29, 2009 T A PAGE 4 of 4 Final Exam 27 pts 05) omplete each of the reactions/questions below in the space provided. a) Do the addition reaction: IUPA name IUPA name b) Stepwise xidtion [] [] 3 c) ydrolyse the amide: 3 N 2 3 Na IUPA name 2 IUPA name IUPA name of ester d) Make a repeat unit of the polyester: e) ydrolysis: Na IUPA name 2 IUPA name of salt formed IUPA name side product f) omplete the reaction IUPA Name of compound Name of reaction 3 2 IUPA Name of compound g) Draw the enol tautomers, circle the most stable 3 IUPA Name of compound