203f00_e3

203f00_e3 - Chemistry 203 Lg (Fall 2000) Quiz #3 November...

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Unformatted text preview: Chemistry 203 Lg (Fall 2000) Quiz #3 November 14, 2000; 11:00-12:20 Last Name: R First Name: Professor Charles E. McKenna INITIAL OF LAST NA ' ‘ Please do not Open this exam until you are told to do so. Write leginy to avoid confusion. GOOD LUCK ! ! 21-25 I will observe the rules of Academic integrity while taking this exam. 1. Student Signature Circle the most nearly correct answer. (4 Pts.) (1) Typical drugs cross cell membranes in their 5 form and bind to their receptor in their _________ form. 0 non-ionized, ionized — ionized, non-ionized — stable, unstable A v 4.2) _ @charged,©charged Q’ a CI Hie W (2) P measures the distribution of a drug between a non-polar solvent and water in a typical QSAR graph, Log (P) increases with a drug’s — hydrophilicity O hydrophobicity — Increase in biological activity — Decrease in biological activity (3) An economics major calculated USC football losses over F/2000 and found the chance for a loss in any one game was 0.8. The probability of losing m the ND and UCLA games this year is: — 0.8 —— 0.4 —- 0.16 6'? 0.64 (4) A company offers a new AIDS drug, specifying that in 21 patients tested, there was a ‘t’ of 1.53. It should report that the probability the drug really works is: (See “t table” on following page.) — 100% — 1% Q 99% ~ Significantly better than 99% Percentage points for the I distribution Area Area to the right Degrees of freedom. v 1 . 2 9.925 3 5.841 4 4 604 5 4 032 6 3.707 7 3.499 8 3.355 . 9 3.250 10 3.159 1 1 3.106 12 3.055 13 3.012 14 2.977 15 2.947 16 2.921 17 2.898 19 2.878 19 2.851 20 2.845 21 2.831 22 2.819 23 2.807 24 2.797 25 2.787 25 2.055 47- 2,779 27 2.052 1| 2 473 2.771 28 2.048 1 2.467 2.753 29 2.045 I 2 452 2.758 30 2.042 2 :57 2.731 40 2 021 I 2 :23 ‘ 2 7:: so 2 000 2 390 1 2 550 For larger values of v treat ( as a z score and use the szaadard normal table (5) A prodrug: — is an active form that is converted into a non-active form in the body - is typically a highly polar or ionic form of a less polar actual drug a is typically an inactive form of a drug, converted internally into the active form — is exemplified by the carrier drug phosphoramide mustard which is converted into propiolaldehyde in the body (6) Factors that should be taken into account when calculating the dose of a drug include: - body weight — age — gender a all of the above r (7) A drug company gets an NDA approval frgm its new drug from the FDA. It is now: A . - ready to start Phase I clinical trials — ready to start toxicology studies in an animal model @ ready to sell the drug on the market — ready to start Phase II clinical trials (8) A key difference between drug clinical trial subjects in Phase I vs. Phase III: — Phase I subjects provide efficacy data, Phase Ill subjects provide pharmacological data 0 Phase 111 subjects are ill, Phase I subjects are healthy — more subjects in Phase I (all ill) - more subjects in Phase III (all healthy) (9) 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: — decrease the value of “t”, the test statistic for a given “level of significance” of the result 0 increase the number of subjects ’ — don’t change the value of “t”, the test statistic for a given “level of significance” of a result - decrease the degrees of freedom associated with our result (10) Reactions of drugs occurring in the liver generally: 9 change the drug into a more polar form toaid excretion — have no effect on its structure — change RCHZOH —) R-CH3 - ~ change R—G—OH “Ge” (11) The difference between pharmacokinetics (PK) and pharmacodynamics (PD): 6 PK measures distribution of ingested drug in different parts of the body - PK measures how well a drug works againsta disease (e.g. virus) — PD measures distribution of ingested drug in different parts of the body — PD measures oral bioavailability 'of a drug (12) Total cost of discovering, developing, getting FDA approval or, and marketing a new drug may be as much as: (9 $500,000,000 - $50,000,000 - $5,000,000 — $500,000 (13) According to Dr. Ebetino, bone loss from osteoporosis becomes especially problematic for women: -— in their childhood — in their teens — who are 18-21 (*9 after their 40’s (14) A newspaper report says that a new drug is “twice as effective” as a competing drug. To evaluate this claim, we would also need to know: —— the confidence level (statistical probability) for a difference of 50% —— the confidence level (statistical probability) for a difference of 100% — the average values for the two drugs —- the confidence level (statistical probability) for a difference of 200% (15) The best source for funding of academic research on discovery of new AIDS drugs is: @ NIH — NSF - an industrial chemical company — The American Heart Foundation (16) A “single blind” study of a new drug means that: — neither subjects nor doctors know who is receiving drug or placebo - subjects but not doctors know who is receiving drug or placebo O doctors but not subjects know who is receiving drug or placebo - both doctors and subjects know who is receiving drug or placebo (17) In the figure shown below, the drug inhibits its target: eversibly - by damaging the substrate - reversibly and non-competitively - reversibly and competitively Covalent Bond (18) The standard deviation measures spread of data from an average or mean. If the data are distributed randomly around the mean, then: - % of all results are +/-1 c of the mean fl% of all results are +/-2 6 of the mean - 95% of all results are +/—3 0' of the mean - a value differing from the mean by 3 0' is probably not significantly different i (19) Some ways to create analogs of a lead drug include: - introducing isosteric groups — simplification of the structure — rigidification of the stucture ‘V - all of the above El 4- Competitive inhibitor 0“ 1"! r; " l r 1/ VI \No inhibitor 3 t,” present /l‘;fw 0 m “MST *' (20) According to the figure above, - Adding more substrate (S) has no effect on the inhibition by I, the drug 0 The drug I binds to the enzyme E fireversibly ' - At infinitely large substrate concentration, the drug has maximum effect - The drug has no effect on V, the rate at which S is turned into product P (21) An enzyme catalyzes break—down of proteins by cleaving the peptide CONH bond. The mechanism has several steps], one of which is shown in the figure below.According to the figure, the role of the His amine group in this step is: - act as an acid to transfer a proton to the peptide 0 act as a base to remove a proton from serine, activating it i - directly attack the peptide C=O bond — form a hydrophobic bond with serine and the peptide -aia.——C—NH-aa~ In the Figure shown above, which panel(s) illustrate potential hydrogen bond interactions between the drug and the receptor site: ‘ - A only - B only - A, B, C and D ‘ a A, C and D only (23) The Induced Fit hypothesis pictures enzyme - drug interactions has involving: - binding like a key into a lock, without change in the enzyme structure during binding 0 binding resulting a modified enzyme structure - binding resulting in a modified drug structure - none of the above (24) Key goals of the medicinal chemist include: - reducing side-effects of a drug - increasing activity of a drug - improving ease of administration of a drug ('5) all of the above Q5) Drugs are mainly deactivated in the: f-) liver ._/ - kidney - pancreas — blood Bonus Question (+4 pts.) Name the compound shown below and explain its use. ...
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This note was uploaded on 07/22/2008 for the course CHEM 203Lxg taught by Professor Mc kenna during the Fall '07 term at USC.

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203f00_e3 - Chemistry 203 Lg (Fall 2000) Quiz #3 November...

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