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203f05_e3_key - Chemistry 203 Lg(Fall 2005 Exam#3 Last Name...

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Unformatted text preview: Chemistry 203 Lg (Fall 2005) Exam #3 Last Name: November 8, 2005; 11:00-12:00 First Name: " Professor Charles E. McKenna Student ID: 1 Professor Amy M. Barrios T.A: l t ‘x”/ INITIAL OF LAST NAME Please do not open this exam until you are told to do so. Write legibly to avoid confusion. GOOD LUCK ! l . Maximum Question # Points TOTAL 100 (+4) - I will observe the rules of Academic integrity while taking this exam. 1’4 W , Student Signature Circle the most nearly correct answer. (4 Pts.) (1) Key natural product drug development strategies include: — Avoiding any expansion or contraction of ring structures in the drug 6 Introducing isosteric groups into the drug structure — Making the drug structure more complex — Making the drug structure more flexible (2) Development of a new drug based on a natural source includes the following steps: 1. Desi gn/synthesis of improved novel drug structures 2. Screen natural sources for biological activity 3. Isolation of active compound from most active natural source. 4. Make structural analogs and determine structure-activity relationships. The logical order would be: ~ 1,2,3,4 — 4,3,2,1 9 2,3,4,1 — 3,2,1,4 (3) Drugs are mainly deactivated in the: — kidney 9 liver — intestine — bladder [O (4) According to the “null hypothesis” in statistics, in a clinical drug trial: _‘ - Control and drug groups should give identical results — Any difference between control, drug groups is significant but psychosomatic in origin (9 Any difference between control, drug groups can be explained as random — It is assumed that the control and drug groups will have significantly different results (5) In the Michaelis-Menten equation for an enzyme-catalyzed reaction E +S => E + P, the term Vm represents: — Reaction rate as a function of the concentration of S — S concentration giving % maximum reaction rate — Maximum reaction rate at a given concentration of S 9 Maximum reaction rate at a given concentration of E (6) One difference between pharmacokinetics (PK) and pharmacodynamics (PD): — PD measures drug concentration in the blood — PK measures drug efficacy — PD measures drug clearance from the body (9 PK measures bioavailability of drug administered (7) Suppose that in a clinical trial of a drug, we get a result for positive effect that is “borderline” significant. If we can raise $$ to repeat the study, we should aim to: — Try lower doses of the drug 9 Increase the number of subjects in the trial — Increase the standard deviation of the trial results — Decrease the number of subjects in the trial LI.) (8) In a typical QSAR graph, Log (l/C) refers to a drug’s hydrophobicity hydrophilicity partition coefficient biological activity (e. g., anti—viral activity) In the diagram below there are clear boxes, shaded circles, and clear circles identifying potential binding sites or sites for interaction with a target receptor protein. The potential H- VMAM "‘ ‘ ‘ u-vfificarkmi of glipinc. The clear squares The clear circles The shaded circles All of the above (10) According to the diagram, modification of the neurotransmitter drug shown to prevent bond rotation will : 6 Likely increase selectivity by restricting binding to only one of the two receptors — Likely decrease selectivity by restricting binding to only one of the two receptors — Facilitate binding to both receptors — Prevent H-bonding interactions between the drug OH group and the receptor OH group (11) Consider the following diagram: — The inhibitor changes Vm 6 The inhibitor changes Km — Adding more substrate S has no effect on the inhibition by I ~ The inhibition is irreversible E . ES ——.._» E ._ p - Iii El - Competitive inhibitor ‘ ,' :7; ’/ _/— .—/' w ,m— ‘ , .7,- i " a r" .A . ‘ .. . ,5 _,” Ne mmbltor .:‘ ;~- press-ct C .J' a_,'"‘ .f _V/ // ./ /_"“ (12) A clinical trial tested a new AIDS drug for efficacy. The mean level of symptoms in a large group of untreated patients is known, ,4 = 9.0. For the drug-treated group (6 patients), the average level (x-bar) is found to be 5.0, with sample standard deviation (5) = 2.5. Given that t = (y - x-bar)/(s/\/n), use the table shown below to select the probability that the drug worked: ~ 95% — 97.5% 9 99.5% _ 100% (94') ~ “f-O ’1.- f/Né Table 11.5 percentage- gomts for (me I distrmutxan , -M, me” A. ~24 M Hr] .‘ = oat-o :41" J. c. Deco" \ ,3 ”I. , ,1 .1 “I, , ,5: ,_ n a ._ J. 4 a. N 3L»: C 5‘ w. T} .‘J? a. 3 a .5 p.- ....,,~ .._,. v-r-~ a :- A3~C€ 5:8; 417-5 :C~; I; l -‘ , > P. 'sfir 0- -y ,1 - . ' _, é ,, LIT. 5.1»: .. . / :I. ’: . :: H :32 . 'z '4‘“: ‘ \ J 4 ' - ~£ \J) i v V—‘J .- ’ ,':. .. C fly“ '2”: N u . - a. .1 «4. c .-._, ~, . m? ,. “V MC , w. _. h - , s , es»... so; a 34:15 ._ - ,-, - M , n - '.—' z " : l , ’ -. c : co... 4 cc. _ 0‘92 , , p...” a .V. ,7 an r, . we 4 2b.; . c... 1 r. 1 r - F. A, A’u- -‘ —_.~ g z; s C .: A 4.5.: . iii-— (13) In the enzyme catalysis mechanism shown below: — His imidazole acts as both a base and a nucleophile — Ser OH acts only as an acid — Water acts as an acid, but not a nucleophile 0 His imidazole acts as both a base and an acid c”. = clan—C NH-aa» / O / (l4) QSAR refers to: 9 Quantitative Structure—Activity Relationships — Qualitative Structure-Activity Relationships — Questionable Structure-Activity Relationships — None of the above (15) Examples of drug metabolic reactions do NOT include: J — Conversion of L—Dopa to dopamine — Hydrolysis of esters and amides J — Loss of methyl groups CH3 from N-CH3 groups in a drug \/ (— l Formation of esters and amides from more polar compounds \c; (16) Bone loss from osteoporosis: (9 Will be a problem for most women older than 40-50 - Affects women only — Decreases in menopausal women — Can be completely avoided solely by increasing dietary calcium (17) The drug shown below will exhibit what kind of enzyme inhibition? Covalent Bond 1—) Irreversible, non-competitive ‘ Irreversible, competitive - Reversible, non-competitive — Reversible, competitive (18) Bone is: — A mineral made of zinc and phosphate —- Dissolved by acid—producing cells (osteoblasts) and reformed by other cells (osteoclasts) 9 Dissolved by acid-producing cells (osteoclasts) and reformed by other cells, (osteoblasts) — A mineral made of calcium and hydroxide (OH) (19) Osteoporosis: g Is treatable by drugs from a class called bisphosphonates — Is a side effect of AIDS - Attacks all bone structures equally — Can be treated by current drugs that block the activity of bone— building cells (osteoblasts) (20) “Placebo effect” refers to: — Patients asking for more drug (Latin, “1 shall (be) please(d)”) — Patients showing a real positive effect from a drug — Patients showing a real negative effect from a drug Q) Patients showing an apparent positive effect from an inactive starch tablet (21) The diagram shows : — Conversion of a nontoxic anti—alcoholism prodrug to its toxic, but active form — Deactivation of a toxic anti~anthrax drug — Synthesis of a relish often used with hot dogs 6 \ Conversion of a nontoxic anti—cancer prodrug to its toxic, active form H N o < \P// c: H2N\P//o c, \ / ——'* I / o/ N “0 \N C! Cl CYCLOPHOSPHAMIDE PHOSPHORAMIDE MUSTARD Fig. 8.20 (22) Consider the possible drug- receptor interactions ABCD shown above. The real drug (free = OH group), binds tightly to its receptor (highly active). Its O—Me form has no activity. These observations taken together are consistent with: — AB — CD _ BC ,0) Either AB or BC (23) In a typical QSAR graph, P refers to a drug’s: — Solubility in octanol Q Solubility in octanol / solubility in H20 -— Solubility in H20/ solubility in octanol - Solubility in H20 10 (24) A Daily Trojan reporter studied the records on illegal use of handicapped parking in the Westwood area. She found that recently the mean frequency / capita for UCLA football players was one standard deviation higher than for a control group© - These results establish a causal relationship between the two sets of x data — The difference is not significant (the Bruin players have reformed!) X — Those results indicate a highly significant difference between the two x sets of data (they’re still at it) ljf?‘ 63 These results indicate that there is about a135%"'¥:hance that the A difference is real. (some of them may be still at it) (25) Referring to the diagram showing two pH-dependent forms (A,B) of a drug, it is more likely that: O H \ l / H —~ fl / .1; / o A B — Only B crosses membranes and binds to the receptor site 9 A crosses membranes, B binds to the receptor site — B crosses membranes, A binds to the receptor site - A and B cross membranes, only A binds to the receptor site BONUS QUESTION l (+ 4 points) If the probability of UCLA winning a game is %, what is their probability of losing both the next games? U = 3/” L. e 1/? MILE t i" ’/r, x ’/'z r ’//4 4117/21») = 974 / '1 t .3 T Z . O K (Ml/J :- 7/9'7/‘7‘ , 7/“ 72 //w IL 3 lé ((4, ”I- e//( = 7//( 11 4 a //L IA» 7 /(g=(/q.;/¢ i GUILJ—lL/lv): 6/" U, “ /14- [L c //o’ L . ...
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