Biochemistry- Complete Exam Test Bank - Exam Questions &
r r r r r r r r r
Answers r
Chapter r1: rIntroduction rto rBiochemistry
1) Which r elements raccount r for r more r than r97% r of rthe rweight r of rmost rorganisms?
A) C, r H, rN, rMg, rO, r S
B) C, r H, rN, rO, r P, rS
C) C, r H, rN
D) Fe, rC, r H, rO, r P
E) Ca2+, rK+, rNa+, rMg2+, rCl-
Answer: r B
Page rRef: r Section r 2
2) Proteins rin rbiological r membranes r may rbe
A) porous.
B) attached rto rthe rmembrane r surface.
C) span r the rmembrane.
D) All rof rthe rabove
E) B rand rC ronly
Answer: r D
Page rRef: r Section r 3
3) Which r statement rabout r cellulose ris rfalse?
A) It r is rthe rmost rabundant r polysaccharide r in rnature.
B) Its rmonomers r are r joined r by rglycosidic r bonds.
C) It r is rpresent r in rthe rstems rof rflowering rplants.
D) The rhydroxyl rgroups rof rneighboring rcellulose rmolecules rinteract rto rform rstrong,
rinsoluble rfibers.
E) It r is ra r branched rpolymer r of rglucose.
Answer: r E
Page rRef: r Section r 3
1
,
4) When rKeq rof ra r reaction r= r1, rthen
A) the rforward r reaction ris rfaster r than r the r reverse r reaction.
B) the rreverse r reaction ris rfaster r than r the r forward r reaction.
C) the rforward rand r reverse r reaction rrate rconstants r are r equal.
D) more r products rare r formed rthan r reactants.
E) fewer r products rare r formed rthan r reactants.
Answer: r C
Page rRef: r Section r 4
5) Which r statement ris rtrue rabout r a r reaction rwith ran requilibrium rconstant, r Keq, requal r to r1000?
A) The r forward rrate rconstant r is r1000 rtimes rgreater r than r the rreverse r rate rconstant.
B) The r forward rrate r constant r is r3 r times rgreater r than rreverse r rate rconstant.
C) The r forward rrate rconstant r is r1000 r times rsmaller rthan rthe rreverse r rate rconstant.
D) The r forward rrate rconstant r is r3 r times rsmaller rthan r the rreverse r rate rconstant.
E) There ris rnot r enough r information r given rto rcompare rthe rforward rand rreverse r rate rconstants.
Answer: r A
Page rRef: r Section r 4
6) The r study r of rthe r energy r changes r during r metabolic rreactions r is rcalled .
A) bioinformatics
B) metabodynamics
C) thermometrics
D) bioenergetics
E) biological r heat r dynamics
Answer: r D
Page rRef: r Section r 4
7) A rspontaneous r chemical r reaction ralways r has r a change.
A) positive r Gibbʹs rfree r energy
B) negative r Gibbʹs rfree r energy
C) positive renthalpy
D) negative renthalpy
E) positive rentropy
Answer: r B
Page rRef: r Section r 4
2
,
8) Prokaryotes rare r valuable rtools r for r biochemists rbecause
A) E. rcoli ris rwell-studied r and rtypical rof rprokaryotes.
B) they rcontain r as rmany r genes r as reukaryotic rcells.
C) many r of rtheir r chromosomes r are r sequenced.
D) they rare r not r very r diverse rorganisms.
E) All rof rthe rabove
Answer: r C
Page rRef: r Section r 6
9) Which rcellular rcomponent rcarries rout roxidation rreactions, rsome rof rwhich rproduce
rhydrogen rperoxide?
A) peroxisomes
B) mitochondria
C) chloroplasts
D) lysosomes
E) vacuoles
Answer: r A
Page rRef: r Section r 8
10) Why ris rit rimportant rthat rthe renzymes rin rlysosomes rare rmore ractive rat racidic rpH rthan rat
rneutral rpH?
A) Since rlysosomes rare rprimarily rfound rin rthe rstomach racid rof rmammals, rtheir
rpH rdependence rallows rfor rmaximum refficiency rfor rthe rdigestion rof
rfoodstuffs.
B) It r prevents rtheir rdiffusion rout rof rthe rlysosomes.
C) It r maximizes r the rinteraction r with rtheir r substrates r which r are ralways r bases.
D) It r prevents rthem r from raccidentally r degrading r the rmacromolecules r in rthe rcytosol.
E) It r allows r for r regulation r of rtheir r uptake r by rthe rmitochondria.
Answer: r D
Page rRef: r Section r 8
11) Molecules rfrom rliving rcells rcannot rbe rsynthesized routside rof rliving
cells. rAnswer: r FALSE
r
Page rRef: r Section r 1
12) Fermentation rin rthe rabsence rof rcells rdemonstrated rthat rmetabolic rprocesses rwere rchemical
rin rnature.
Answer: r TRUE
Page rRef: r Section r 1
3
,
13) Enzymes r are rprotein r catalysts rthat r form ran rintermediate r with ra r substrate rthat r fits r into r it.
Answer: r TRUE
Page rRef: r Section r 1
14) The rmodified rlock-and-key rtheory rof renzyme raction rproposed rby rEmil rFischer rhas
rbeen rcompletely rreplaced rby rmore rmodern rideas rof rcatalysis.
Answer: r FALSE
Page rRef: r Section r 1
15) Enzymes rare rnot ras refficient ras rmost rcatalysts rused rin rorganic rchemistry, rsince rthey
rmust rfunction rat rbody rtemperature.
Answer: r FALSE
Page rRef: r Section r 1
16) Bioinformatics rhas rpermitted rrapid radvances rin rour runderstanding rof
rstructural rmacromolecules rfrom rliving rcells.
Answer: r TRUE
Page rRef: r Section r 1
17) The rrole rof rDNA ras rthe rgenetic rmaterial rwas rconfirmed rby rtransforming rStreptococci rin
rexperiments rperformed rseveral ryears rafter rthe rfamous rWatson rand rCrick rdescription rof
rDNA rstructure.
Answer: r FALSE
Page rRef: r Section r 1
18) Crick rreferred rto rthe rflow rof rinformation rfrom rnucleic racid rto rprotein ras rthe rCentral
Dogma. rAnswer: r TRUE
r
Page rRef: r Section r 1
19) Functional rgroups rdescribe rone ror rmore rportions rof rorganic rcompounds rfound rin rliving
cells. rAnswer: r TRUE
r
Page rRef: r Section r 2
20) A rphosphate rester rcontains ra rphosphate rfunctional
group. rAnswer: r TRUE
r
Page rRef: r Section r 2
21) Under rmost rbiological rconditions, racid rgroups rand ramino rgroups rare rfully
protonated. rAnswer: r FALSE
r
Page rRef: r Section r 2
4
r r r r r r r r r
Answers r
Chapter r1: rIntroduction rto rBiochemistry
1) Which r elements raccount r for r more r than r97% r of rthe rweight r of rmost rorganisms?
A) C, r H, rN, rMg, rO, r S
B) C, r H, rN, rO, r P, rS
C) C, r H, rN
D) Fe, rC, r H, rO, r P
E) Ca2+, rK+, rNa+, rMg2+, rCl-
Answer: r B
Page rRef: r Section r 2
2) Proteins rin rbiological r membranes r may rbe
A) porous.
B) attached rto rthe rmembrane r surface.
C) span r the rmembrane.
D) All rof rthe rabove
E) B rand rC ronly
Answer: r D
Page rRef: r Section r 3
3) Which r statement rabout r cellulose ris rfalse?
A) It r is rthe rmost rabundant r polysaccharide r in rnature.
B) Its rmonomers r are r joined r by rglycosidic r bonds.
C) It r is rpresent r in rthe rstems rof rflowering rplants.
D) The rhydroxyl rgroups rof rneighboring rcellulose rmolecules rinteract rto rform rstrong,
rinsoluble rfibers.
E) It r is ra r branched rpolymer r of rglucose.
Answer: r E
Page rRef: r Section r 3
1
,
4) When rKeq rof ra r reaction r= r1, rthen
A) the rforward r reaction ris rfaster r than r the r reverse r reaction.
B) the rreverse r reaction ris rfaster r than r the r forward r reaction.
C) the rforward rand r reverse r reaction rrate rconstants r are r equal.
D) more r products rare r formed rthan r reactants.
E) fewer r products rare r formed rthan r reactants.
Answer: r C
Page rRef: r Section r 4
5) Which r statement ris rtrue rabout r a r reaction rwith ran requilibrium rconstant, r Keq, requal r to r1000?
A) The r forward rrate rconstant r is r1000 rtimes rgreater r than r the rreverse r rate rconstant.
B) The r forward rrate r constant r is r3 r times rgreater r than rreverse r rate rconstant.
C) The r forward rrate rconstant r is r1000 r times rsmaller rthan rthe rreverse r rate rconstant.
D) The r forward rrate rconstant r is r3 r times rsmaller rthan r the rreverse r rate rconstant.
E) There ris rnot r enough r information r given rto rcompare rthe rforward rand rreverse r rate rconstants.
Answer: r A
Page rRef: r Section r 4
6) The r study r of rthe r energy r changes r during r metabolic rreactions r is rcalled .
A) bioinformatics
B) metabodynamics
C) thermometrics
D) bioenergetics
E) biological r heat r dynamics
Answer: r D
Page rRef: r Section r 4
7) A rspontaneous r chemical r reaction ralways r has r a change.
A) positive r Gibbʹs rfree r energy
B) negative r Gibbʹs rfree r energy
C) positive renthalpy
D) negative renthalpy
E) positive rentropy
Answer: r B
Page rRef: r Section r 4
2
,
8) Prokaryotes rare r valuable rtools r for r biochemists rbecause
A) E. rcoli ris rwell-studied r and rtypical rof rprokaryotes.
B) they rcontain r as rmany r genes r as reukaryotic rcells.
C) many r of rtheir r chromosomes r are r sequenced.
D) they rare r not r very r diverse rorganisms.
E) All rof rthe rabove
Answer: r C
Page rRef: r Section r 6
9) Which rcellular rcomponent rcarries rout roxidation rreactions, rsome rof rwhich rproduce
rhydrogen rperoxide?
A) peroxisomes
B) mitochondria
C) chloroplasts
D) lysosomes
E) vacuoles
Answer: r A
Page rRef: r Section r 8
10) Why ris rit rimportant rthat rthe renzymes rin rlysosomes rare rmore ractive rat racidic rpH rthan rat
rneutral rpH?
A) Since rlysosomes rare rprimarily rfound rin rthe rstomach racid rof rmammals, rtheir
rpH rdependence rallows rfor rmaximum refficiency rfor rthe rdigestion rof
rfoodstuffs.
B) It r prevents rtheir rdiffusion rout rof rthe rlysosomes.
C) It r maximizes r the rinteraction r with rtheir r substrates r which r are ralways r bases.
D) It r prevents rthem r from raccidentally r degrading r the rmacromolecules r in rthe rcytosol.
E) It r allows r for r regulation r of rtheir r uptake r by rthe rmitochondria.
Answer: r D
Page rRef: r Section r 8
11) Molecules rfrom rliving rcells rcannot rbe rsynthesized routside rof rliving
cells. rAnswer: r FALSE
r
Page rRef: r Section r 1
12) Fermentation rin rthe rabsence rof rcells rdemonstrated rthat rmetabolic rprocesses rwere rchemical
rin rnature.
Answer: r TRUE
Page rRef: r Section r 1
3
,
13) Enzymes r are rprotein r catalysts rthat r form ran rintermediate r with ra r substrate rthat r fits r into r it.
Answer: r TRUE
Page rRef: r Section r 1
14) The rmodified rlock-and-key rtheory rof renzyme raction rproposed rby rEmil rFischer rhas
rbeen rcompletely rreplaced rby rmore rmodern rideas rof rcatalysis.
Answer: r FALSE
Page rRef: r Section r 1
15) Enzymes rare rnot ras refficient ras rmost rcatalysts rused rin rorganic rchemistry, rsince rthey
rmust rfunction rat rbody rtemperature.
Answer: r FALSE
Page rRef: r Section r 1
16) Bioinformatics rhas rpermitted rrapid radvances rin rour runderstanding rof
rstructural rmacromolecules rfrom rliving rcells.
Answer: r TRUE
Page rRef: r Section r 1
17) The rrole rof rDNA ras rthe rgenetic rmaterial rwas rconfirmed rby rtransforming rStreptococci rin
rexperiments rperformed rseveral ryears rafter rthe rfamous rWatson rand rCrick rdescription rof
rDNA rstructure.
Answer: r FALSE
Page rRef: r Section r 1
18) Crick rreferred rto rthe rflow rof rinformation rfrom rnucleic racid rto rprotein ras rthe rCentral
Dogma. rAnswer: r TRUE
r
Page rRef: r Section r 1
19) Functional rgroups rdescribe rone ror rmore rportions rof rorganic rcompounds rfound rin rliving
cells. rAnswer: r TRUE
r
Page rRef: r Section r 2
20) A rphosphate rester rcontains ra rphosphate rfunctional
group. rAnswer: r TRUE
r
Page rRef: r Section r 2
21) Under rmost rbiological rconditions, racid rgroups rand ramino rgroups rare rfully
protonated. rAnswer: r FALSE
r
Page rRef: r Section r 2
4
