BIOCHEM EXAM 1 REVIEW QUESTIONS AND CORRECT VERIFIED ANSWERS

BIOCHEM EXAM 1 REVIEW QUESTIONS
AND CORRECT VERIFIED ANSWERS
WhatA2isA2theA2pHA2ofA2aA2solutionA2ofA20.050A2MA2HCl?A2-A2Ans--pHA2=A2-log[H+]
pHA2=A2-log[0.05]A2=A21.30

TheA2CentralA2"Dogma"A2ofA2BiochemistryA2isA2basedA2onA2theA2flowA2ofA2geneticA2inform
ationA2beginningA2withA2informationA2foundA2inA2____A2usedA2toA2createA2moleculesA2ofA2_
___,A2whichA2areA2ultimatelyA2usedA2toA2synthesizeA2___A2-A2Ans--
DNA,A2RNAA2,A2ProteinA2.

TheA2pHA2ofA2aA2sampleA2ofA2bloodA2isA27.4,A2whileA2gastricA2juiceA2isA2pHA21.4.A2TheA2blo
odA2sampleA2hasA2___________A2timesA2lowerA2[H+]A2thanA2theA2gastricA2juice?A2-A2Ans--
EveryA21A2unitA2changeA2inA2pHA2isA2equivalentA2toA2aA210-foldA2increaseA2inA2[H+].
7.4-1.4A2=A26A2pHA2units
10^6A2=A21,000,000

AccordingA2toA2theA2Henderson-
HasselbalchA2equation,A2theA2pHA2isA2equalA2toA2theA2_____________A2whenA2theA2conc
entrationA2ofA2theA2conjugateA2baseA2isA2equalA2toA2theA2concentrationA2ofA2theA2weakA2ac
id.A2-A2Ans--pKa

InA2theA2four-stepA2molecularA2hierarchyA2ofA2structure,A2theA2__________________A2is/
areA2theA2secondA2smallest.A2-A2Ans--macromolecule

PhosphoricA2acidA2(H3PO4)A2isA2tribasic,A2withA2pKa'sA2ofA22.14,A26.86,A2andA212.4.A2The
A2chargeA2ofA2theA2ionicA2formA2ofA2theA2conjugateA2baseA2thatA2predominatesA2atA2pHA28A
2isA2__________.A2(SeeA2figureA22-16A2forA2aA2hint)A2-A2Ans---2


InA2general,A2bacterialA2cellsA2areA2___A2thanA2animalA2cells.A2-A2Ans--smaller

TheA2pHA2ofA2aA2solutionA2ofA20.200A2MA2NaOHA2isA2-A2Ans--pOHA2=A2-log[OH-]
pOHA2=A2-log[0.2]A2=A20.70
pHA2+A2pOHA2=A214
pH=14A2-A2pOHA2=A214-0.7A2=A213.3

WhichA2ofA2theA2theA2followingA2benefitsA2doA2enzymaticA2catalystsA2NOTA2offer?A2-
A2Ans--abilityA2toA2alterA2ΔG°


ApproximateA2theA2finalA2pHA2ofA2aA2solutionA2whenA21.5A2molesA2ofA2aA2weakA2acidA2isA2a
ddedA2toA2waterA2toA2aA2finalA2volumeA2ofA21LA2(KaA2=A25.67A2xA210-8).A2-A2Ans--
5.67A2xA210-8A2=A2x2/1.5
x2A2=A23.969A2xA210-8
xA2=A21.99A2xA210-4

, -logA2(1.99A2xA210-4)A2=A23.54

TheA2pKaA2ofA2aceticA2acidA2(CH3COOH)A2isA24.76.A2IfA2aA2solutionA2ofA2aceticA2acidA2isA2
atA2aA2pHA2ofA25.56,A2theA2ratioA2ofA2conjugateA2baseA2toA2acidA2isA2-A2Ans--Henderson-
HasselbalchA2equationA2statesA2pHA2=A2pKaA2+A2log([conjugateA2base]/[acid])
5.56A2=A24.76A2+A2log([conjugateA2base]/[acid])
0.8A2=A2log([conjugateA2base]/[acid])
10^0.8A2=A2[conjugateA2base]/[acid]
6.31A2=A2[conjugateA2base]/[acid]

OfA2theA2followingA2structuresA2foundA2insideA2aA2eukaryoticA2organism,A2whichA2areA2theA
2largest?
macromolecules
supramolecularA2complexes
monomericA2units
cells
organellesA2-A2Ans--cells

SynthesisA2ofA2complexA2molecules
willA2typicallyA2haveA2aA2negativeA2standardA2deltaA2G.
A2requiresA2anA2inputA2ofA2energy.
neverA2occursA2inA2cells.
isA2oftenA2thermodynamicallyA2favorable.
isA2anA2exergonicA2process.A2-A2Ans--requiresA2anA2inputA2ofA2energy.

AllA2ofA2theA2statementsA2areA2trueA2regardingA2catalystsA2except
CatalystsA2increaseA2standardA2deltaA2G
CatalystsA2lowerA2theA2activationA2freeA2energyA2ofA2aA2reaction
CatalystsA2increaseA2theA2rateA2ofA2aA2reaction
allA2ofA2theseA2statementsA2areA2trueA2ofA2catalysts
CatalystsA2canA2beA2enzymesA2-A2Ans--Correct!A2CatalystsA2increaseA2standardA2deltaA2G

AllA2ofA2theA2followingA2areA2characteristicsA2ofA2livingA2matterA2except
theA2abilityA2toA2respondA2toA2surroundings
theA2coordinationA2ofA2interactionsA2ofA2componentsA2beingA2coordinated
theA2capacityA2forA2self-replication
A2theA2abilityA2toA2createA2energy
aA2highA2degreeA2ofA2complexityA2-A2Ans--theA2abilityA2toA2createA2energy

AA2seriesA2ofA2enzymaticallyA2catalyzedA2chemicalA2reactionsA2thatA2areA2allA2relatedA2isA2
referredA2toA2asA2a
metabolicA2pathway
allostericA2reaction
centralA2dogma
feedbackA2inhibition
coordinatedA2setA2-A2Ans--metabolicA2pathway