Bioc 2580 Midterm Exam Questions With Correct Answers.

Bioc 2580 Midterm Exam Questions With
Correct Answers
very ||non-polar ||side ||chains ||- ||CORRECT ||ANSWER✔✔-ala, ||val, ||leu, ||ile, ||met, ||phe

- ||side ||chains ||are ||dominated ||by ||non-polar ||and ||hydrophobic ||hydrocarbons



moderately ||non-polar ||- ||CORRECT ||ANSWER✔✔-gly, ||cys, ||pro, ||tyr, ||trp

-gly: ||single ||H, ||not ||enough ||to ||be ||very ||non-polar

-cys: ||slightly ||polar ||SH

-pro: ||side ||chain ||links ||to ||N ||and ||alpha ||C, ||polar ||non ||moderates ||non-polar ||hydrocarbon

-tyr ||& ||trp: ||single ||polar ||group ||that ||partly ||offsets ||very ||non-polar ||benzene



polar ||uncharged ||- ||CORRECT ||ANSWER✔✔-ser, ||thr, ||asn, ||gln

-ser ||& ||thr: ||side ||chains ||with ||OH

asn ||& ||gln: ||polar ||amide ||groups

-don't ||hain ||or ||lose ||H+ ||in ||aqueous ||solution ||at ||pH ||7, ||so ||they're ||uncharged

-good ||H ||bond ||acceptors



very ||polar ||positively ||charged ||- ||CORRECT ||ANSWER✔✔-His, ||lys ||and ||arg

- ||contain ||weak ||bases ||that ||gain ||H+

-charge ||makes ||them ||very ||polar, ||overriding ||non-polar ||hydrocarbons



very ||polar ||negatively ||charged ||- ||CORRECT ||ANSWER✔✔--have ||carboxylic ||acid ||groups ||that ||
lose ||H+

, henderson-hasselbalch ||equation ||- ||CORRECT ||ANSWER✔✔-pH=pKa+log ||[deprotonated] ||/ ||
[protonated]



deprotonated ||- ||CORRECT ||ANSWER✔✔-pH ||is ||one ||unit ||higher ||than ||pKa



protonated ||- ||CORRECT ||ANSWER✔✔-pH ||is ||one ||unit ||below ||pKa



partition ||chromatography ||- ||CORRECT ||ANSWER✔✔--stationary ||phase ||that ||hydrogen ||bonds ||
to ||polar ||AAs

-mobile ||phase ||that ||flows ||past ||the ||particles ||and ||is ||non-polar

-polar ||AA ||spend ||more ||time ||hydrogen ||bonded ||and ||move ||slowly

-nonpolar ||AA ||spend ||more ||time ||in ||solvent ||and ||move ||almost ||as ||fast ||as ||solvent



thin ||layer ||chromatography ||- ||CORRECT ||ANSWER✔✔--silica ||gel ||is ||spread ||in ||a ||thin ||layer ||on
||a ||plastic ||sheet, ||this ||is ||the ||polar ||stationary ||phase



-samples ||are ||applied ||to ||lower ||edge ||and ||placed ||in ||solvent

-solvent ||soaks ||up ||sheet ||and ||non-polar ||AA ||move ||with ||the ||solvent

-highest ||point ||reached ||by ||solvent ||is ||the ||solvent ||front

-relative ||mobility: ||RF=XB ||(distance ||travelled ||by ||sample) ||/ ||XF(distance ||travelled ||by ||solvent

-nonpolar ||AA ||have ||high ||RF ||(mobile)

-polar ||AA ||have ||low ||RF ||(stationary)



column ||chromatography ||- ||CORRECT ||ANSWER✔✔--sample ||is ||added

-buffer ||is ||added, ||carrying ||sample ||out

-contents ||of ||collection ||is ||analysed ||and ||plotted

-volume ||of ||buffer ||needed ||to ||move ||a ||component ||through ||the ||column ||is ||the ||elution ||
volume