,Chapter 1 m Introduction to Biochemistry of life
m m m m
1) Which m elements maccount m for m more m than m 97% m of mthe m weight m of mmost morganisms?
A) C, mH, mN, mMg, mO, mS
B) C, mH, mN, mO, mP, mS
C) C, mH, mN
D) Fe, mC, mH, mO, mP
E) Ca2+, m K+, m Na+, m Mg2+, m Cl-
Answer: m B
Page mRef: mSection m2
2) Proteins min mbiological m membranes m may m be
A) porous.
B) attached m to mthe m membrane m surface.
C) span m the m membrane.
D) All m of mthe mabove
E) B mand mC monly
Answer: m D
Page mRef: mSection m3
3) Which m statement mabout m cellulose m is mfalse?
A) It m is mthe mmost mabundant m polysaccharide m in mnature.
B) Its mmonomers m are m joined m by mglycosidic m bonds.
C) It m is mpresent m in mthe mstems mof mflowering m plants.
D) The m hydroxyl m groups m of mneighboring m cellulose m molecules m interact m to mform m strong,
m insolublemfibers.
E) It m is ma m branched mpolymer m of mglucose.
Answer: m E
Page mRef: mSection m3
1
,4) When mKeq mof ma m reaction m= m1, mthen
A) the m forward m reaction mis mfaster m than m the m reverse m reaction.
B) the m reverse m reaction mis mfaster m than m the m forward m reaction.
C) the m forward m and m reverse m reaction mrate m constants m are m equal.
D) more m products mare m formed m than m reactants.
E) fewer m products mare m formed m than m reactants.
Answer: m C
Page mRef: mSection m4
5) Which m statement mis mtrue mabout m a m reaction mwith man mequilibrium m constant, m Keq, mequal m to m1000?
A) The m forward m rate m constant m is m1000 m times mgreater m than m the m reverse m rate mconstant.
B) The m forward m rate m constant m is m3 m times mgreater m than m reverse m rate mconstant.
C) The m forward m rate m constant m is m1000 m times msmaller mthan m the m reverse m rate m constant.
D) The m forward m rate m constant m is m3 m times msmaller mthan m the m reverse m rate mconstant.
E) There m is mnot m enough m information m given m to mcompare m the m forward m and m reverse m rate m constants.
Answer: m A
Page mRef: mSection m4
6) The m study m of mthe m energy m changes m during m metabolic m reactions m is mcalled .
A) bioinformatics
B) metabodynamics
C) thermometrics
D) bioenergetics
E) biological m heat m dynamics
Answer: m D
Page mRef: mSection m4
7) A m spontaneous m chemical m reaction malways m has m a change.
A) positive m Gibbʹs m free m energy
B) negative m Gibbʹs m free m energy
C) positive m enthalpy
D) negative m enthalpy
E) positive m entropy
Answer: m B
Page mRef: mSection m4
2
, 8) Prokaryotes m are m valuable m tools m for m biochemists m because
A) E. mcoli mis mwell-studied m and mtypical mof mprokaryotes.
B) they mcontain m as mmany m genes m as m eukaryotic m cells.
C) many m of mtheir m chromosomes m are m sequenced.
D) they mare m not m very m diverse morganisms.
E) All m of mthe mabove
Answer: m C
Page mRef: mSection m6
9) Which m cellular m component m carries m out m oxidation m reactions, m some m of mwhich m produce
m hydrogenmperoxide?
A) peroxisomes
B) mitochondria
C) chloroplasts
D) lysosomes
E) vacuoles
Answer: m A
Page mRef: mSection m8
10) Why m is mit m important m that m the m enzymes m in mlysosomes m are m more mactive m at m acidic m pH
m than m at m neutralmpH?
A) Since mlysosomes m are m primarily m found m in mthe m stomach macid m of mmammals,
m their m pHmdependence m allows m for m maximum mefficiency m for m the m digestion
m of mfoodstuffs.
B) It m prevents m their m diffusion mout mof mthe m lysosomes.
C) It m maximizes m the m interaction m with mtheir m substrates m which m are m always m bases.
D) It m prevents m them m from m accidentally m degrading m the mmacromolecules m in mthe m cytosol.
E) It m allows m for m regulation m of mtheir m uptake m by mthe m mitochondria.
Answer: m D
Page mRef: mSection m8
11) Molecules m from m living m cells m cannot m be msynthesized m outside m of
mliving m cells.mAnswer: m FALSE
Page mRef: mSection m1
12) Fermentation m in mthe m absence m of mcells m demonstrated m that m metabolic m processes m were
mchemical m inmnature.
Answer: m TRUE
Page mRef: mSection m1
3
m m m m
1) Which m elements maccount m for m more m than m 97% m of mthe m weight m of mmost morganisms?
A) C, mH, mN, mMg, mO, mS
B) C, mH, mN, mO, mP, mS
C) C, mH, mN
D) Fe, mC, mH, mO, mP
E) Ca2+, m K+, m Na+, m Mg2+, m Cl-
Answer: m B
Page mRef: mSection m2
2) Proteins min mbiological m membranes m may m be
A) porous.
B) attached m to mthe m membrane m surface.
C) span m the m membrane.
D) All m of mthe mabove
E) B mand mC monly
Answer: m D
Page mRef: mSection m3
3) Which m statement mabout m cellulose m is mfalse?
A) It m is mthe mmost mabundant m polysaccharide m in mnature.
B) Its mmonomers m are m joined m by mglycosidic m bonds.
C) It m is mpresent m in mthe mstems mof mflowering m plants.
D) The m hydroxyl m groups m of mneighboring m cellulose m molecules m interact m to mform m strong,
m insolublemfibers.
E) It m is ma m branched mpolymer m of mglucose.
Answer: m E
Page mRef: mSection m3
1
,4) When mKeq mof ma m reaction m= m1, mthen
A) the m forward m reaction mis mfaster m than m the m reverse m reaction.
B) the m reverse m reaction mis mfaster m than m the m forward m reaction.
C) the m forward m and m reverse m reaction mrate m constants m are m equal.
D) more m products mare m formed m than m reactants.
E) fewer m products mare m formed m than m reactants.
Answer: m C
Page mRef: mSection m4
5) Which m statement mis mtrue mabout m a m reaction mwith man mequilibrium m constant, m Keq, mequal m to m1000?
A) The m forward m rate m constant m is m1000 m times mgreater m than m the m reverse m rate mconstant.
B) The m forward m rate m constant m is m3 m times mgreater m than m reverse m rate mconstant.
C) The m forward m rate m constant m is m1000 m times msmaller mthan m the m reverse m rate m constant.
D) The m forward m rate m constant m is m3 m times msmaller mthan m the m reverse m rate mconstant.
E) There m is mnot m enough m information m given m to mcompare m the m forward m and m reverse m rate m constants.
Answer: m A
Page mRef: mSection m4
6) The m study m of mthe m energy m changes m during m metabolic m reactions m is mcalled .
A) bioinformatics
B) metabodynamics
C) thermometrics
D) bioenergetics
E) biological m heat m dynamics
Answer: m D
Page mRef: mSection m4
7) A m spontaneous m chemical m reaction malways m has m a change.
A) positive m Gibbʹs m free m energy
B) negative m Gibbʹs m free m energy
C) positive m enthalpy
D) negative m enthalpy
E) positive m entropy
Answer: m B
Page mRef: mSection m4
2
, 8) Prokaryotes m are m valuable m tools m for m biochemists m because
A) E. mcoli mis mwell-studied m and mtypical mof mprokaryotes.
B) they mcontain m as mmany m genes m as m eukaryotic m cells.
C) many m of mtheir m chromosomes m are m sequenced.
D) they mare m not m very m diverse morganisms.
E) All m of mthe mabove
Answer: m C
Page mRef: mSection m6
9) Which m cellular m component m carries m out m oxidation m reactions, m some m of mwhich m produce
m hydrogenmperoxide?
A) peroxisomes
B) mitochondria
C) chloroplasts
D) lysosomes
E) vacuoles
Answer: m A
Page mRef: mSection m8
10) Why m is mit m important m that m the m enzymes m in mlysosomes m are m more mactive m at m acidic m pH
m than m at m neutralmpH?
A) Since mlysosomes m are m primarily m found m in mthe m stomach macid m of mmammals,
m their m pHmdependence m allows m for m maximum mefficiency m for m the m digestion
m of mfoodstuffs.
B) It m prevents m their m diffusion mout mof mthe m lysosomes.
C) It m maximizes m the m interaction m with mtheir m substrates m which m are m always m bases.
D) It m prevents m them m from m accidentally m degrading m the mmacromolecules m in mthe m cytosol.
E) It m allows m for m regulation m of mtheir m uptake m by mthe m mitochondria.
Answer: m D
Page mRef: mSection m8
11) Molecules m from m living m cells m cannot m be msynthesized m outside m of
mliving m cells.mAnswer: m FALSE
Page mRef: mSection m1
12) Fermentation m in mthe m absence m of mcells m demonstrated m that m metabolic m processes m were
mchemical m inmnature.
Answer: m TRUE
Page mRef: mSection m1
3
