BIOCHEM - MODULE 1 QUESTIONS
WITH COMPLETE SOLUTIONS
What jjis jjthe jjformula jjused jjto jjcalculate jjpH? jj- jjAnswerpH jj= jj-log[H+]
If jjyou jjhave jja jjsolution jjthat jjis jja jjpH jjof jj3.6, jjwhat jjis jjthe jjpOH jjand jjwhat jjis jjpOH
jjmeasuring? jj- jjAnswerpH jj+ jjpOH jj= jj14
The jjpOH jjwould jjbe jj10.4. jjSimilar jjto jjpH, jjthe jjpOH jjmeasures jjthe jjhydroxyl jjion
jjconcentration jjin jjsolution jj
If jja jjsolution jjis jjacidic jjthen jjyou jjwould jjexpect jjthere jjto jjbe jjfew jjOH- jjions jjand jjthus
jjpresent jjin jja jjvery jjlow jjconcentration. jjA jjpOH jjof jj10.4 jjis jjequal jjto jj[OH-] jj= jj4 jjx jj10^-
11 jjM
Why jjis jjpure jjwater jjneutral jjand jjat jja jjpH jj= jj7? jj- jjAnswerIn jjfreshly jjdistilled jjwater,
jjthere jjis jjan jjequal jjconcentration jjof jj[H^+] jjand jj[OH^-].
With jjincreasing jjCO2 jjconcentration jjin jjthe jjatmosphere jjwhat jjwould jjyou jjexpect
jjwould jjhappen jjto jjthe jjpH jjof jjlakes, jjrivers, jjand jjoceans? jj- jjAnswerOne jjwould jjpredict
jjthe jjlarge jjbodies jjof jjwater jjto jjequilibrate jjwith jjatmospheric jjCO_2 jjand jjbecome jjmore
jjacidic.
Sea jjwater jjis jjabout jj______________ jjtimes jjmore jjbasic jjthan jjblack jjcoffee. jj-
jjAnswer1,000
What jjis jjthe jjpH jjrange jjof jjblood? jj- jjAnswer7.35-7.45
For jja jjsolution jjof jjthe jjweak jjacid jjHA, jjwhat jjare jjthe jjformulas jjused jjto jjcalculate jjKa jj=
jj____________ jjand jjpKa jj= jj____________? jj- jjAnswerKa jj= jj[H+][A-] jj/ jj[HA]
pKa jj= jj-log jj[Ka]
The jjpK jjof jjacetic jjacid jjis jjpK jj= jj4.76. jjFor jja jj0.1 jjM jjsolution jjof jjacetic jjacid jjat jja jjpH jj=
jj4.76 jjwhat jjis jjthe jjconcentration jjof jj[H+]? jj- jjAnswer[H+] jj= jj[CH3COO-] jj= jj0.05 jjM. jjFor
jjsolutions jjof jjweak jjacids jjand jjbases jjwith jja jjpH jj= jjpK jjthe jjconcentrations jjof jjH+ jjand
jjOH- jjare jjequal.
Write jjthe jjHenderson-Hasselbalch jjequation. jj- jjAnswerpH jj= jjpKa jj+ jjlog([A-]/[HA])
, Why jjare jjweak jjacids jjand jjbases jjgood jjbuffers jjand jjhow jjdoes jja jjbuffer jjwork? jj-
jjAnswerWeak jjacids jjand jjbases jjonly jjpartially jjdissociate jjinto jjH+ jjand jjconjugate
jjbase. jjThey jjare jjgood jjbuffers jjbecause jjin jjsolution jjthere jjis jja jjpH jj= jjpK jjat jjwhich jjthe
jjweak jjacid jjor jjbase jjis jjonly jj50% jjdissociated jjand jjcould jjdonate jjor jjaccept jjhydrogen
jjions jjif jja jjreaction jjin jjthe jjsolution jjused jjor jjcreated jjmore jjH+. jjBuffers jjwork jjby
jjaccepting jjor jjdonating jjH+, jjwhen jjat jjpH jj= jjpK jjand jjpreventing jjrapid jjchanges jjin jjthe
jjsolution jjpH
What jjare jjthe jjthree jjmajor jjbuffering jjsystems jjused jjin jjour jjbodies? jj-
jjAnswerPhosphate, jjproteins, jjbicarbonate
When jjwe jjexercise jjwe jjproduce jjCO2 jjand jjlactic jjacid jjin jjour jjmuscle jjtissues. jjHow
jjdo jjour jjbodies jjprevent jjwide jjfluctuations jjin jjblood jjpH jjfrom jjexercise? jj- jjAnswerThe
jjbicarbonate jjbuffer jjhelps jjto jjmaintain jja jjconstant jjblood jjpH jjbut jjbecause jjits jjpK jjis
jjover jj1 jjpH jjunit jjfrom jjthe jjblood jjpH jj7.4. jjBecause jjof jjthis jjour jjbodies jjhave jjevolved
jja jjcomplex jjsystem jjto jjprevent jjbuild jjup jjof jjCO2 jjconcentrations jjin jjblood jjby jjexpiring
jjthe jjexcess jjCO2 jjfrom jjour jjlungs jjand jjby jjexcreting jjit jjin jjour jjurine
If jjan jjindividual jjweak jjbond jjcan jjbe jjbroken jjat jjroom jjtemperature, jjhow jjdo jjweak
jjbonds jjwork jjto jjmaintain jjprotein jjand jjDNA jjstructure? jj- jjAnswerWeak jjbonds jjwork jjby
jjstrength jjin jjnumbers. jjThe jjenergy jjto jjbreak jjhundreds jjor jjthousands jjof jjweak jjbonds
jjcan jjexceed jjthe jjenergy jjrequired jjto jjbreak jja jjcovalent jjbond, jjthus jjmany jjweak
jjbonds jjhelp jjmaintain jjprotein jjand jjDNA jjstructure
Ionic jjbonds, jjhydrogen jjbonds, jjand jjvan jjder jjWaal's jjinteractions jjare jjall jjweak jjbonds
jjthat jjform jjby jjattraction jjbetween jjtwo jjatoms jjor jjmolecules. jjWhat jjis jjthe jjname jjof jjthe
jjweak jjforce jjthat jjdoes jjnot jjwork jjby jjattraction? jjDescribe jjwhy. jj- jjAnswerThe jjname jjof
jjthe jjweak jjinteraction jjis jjthe jjhydrophobic jjeffect. jjIt jjworks jjby jjcreating jjmore jjentropy
jjin jjwater jjsolutions. jjAn jjimportant jjexample jjis jjthe jjformation jjof jjcellular jjmembranes
jjbetween jjlipids jjthat jjare jjinsoluble jjin jjwater. jjAggregation jjbetween jjthe jjlong,
jjuncharged jjlipid jjside jjchains jjreleases jjthe jjsurrounding jjwater jjmolecules jjback jjinto
jjbulk jjwater jjincreasing jjthe jjoverall jjentropy jjof jjthe jjsystem
Individual jjweak jjbonds jjare jjapproximately jj__________-fold jjweaker jjthan jjstrong
jjcovalent jjbonds. jj- jjAnswer10
The jjweak jjvan jjder jjWaal's jjforce jjcreates jjits jjown jjattractive jjforce jjbetween jjatoms
jjdue jjto jj_____________ jj_____________ jjformed jjby jjrepulsion jjbetween jjelectrons. jj-
jjAnswerinduced jjdipoles
The jjunusually jjhigh jjsurface jjtension jjproperty jjof jjwater jjthat jjallows jjwater jjstriders jjto
jj"walk" jjon jjwater jjis jjdue jjto jj___________________________________. jj-
jjAnswerhydrogen jjbonding jjnetworks
A jjbuffer jjis jja jj______________ jjreservoir. jj- jjAnswerproton
WITH COMPLETE SOLUTIONS
What jjis jjthe jjformula jjused jjto jjcalculate jjpH? jj- jjAnswerpH jj= jj-log[H+]
If jjyou jjhave jja jjsolution jjthat jjis jja jjpH jjof jj3.6, jjwhat jjis jjthe jjpOH jjand jjwhat jjis jjpOH
jjmeasuring? jj- jjAnswerpH jj+ jjpOH jj= jj14
The jjpOH jjwould jjbe jj10.4. jjSimilar jjto jjpH, jjthe jjpOH jjmeasures jjthe jjhydroxyl jjion
jjconcentration jjin jjsolution jj
If jja jjsolution jjis jjacidic jjthen jjyou jjwould jjexpect jjthere jjto jjbe jjfew jjOH- jjions jjand jjthus
jjpresent jjin jja jjvery jjlow jjconcentration. jjA jjpOH jjof jj10.4 jjis jjequal jjto jj[OH-] jj= jj4 jjx jj10^-
11 jjM
Why jjis jjpure jjwater jjneutral jjand jjat jja jjpH jj= jj7? jj- jjAnswerIn jjfreshly jjdistilled jjwater,
jjthere jjis jjan jjequal jjconcentration jjof jj[H^+] jjand jj[OH^-].
With jjincreasing jjCO2 jjconcentration jjin jjthe jjatmosphere jjwhat jjwould jjyou jjexpect
jjwould jjhappen jjto jjthe jjpH jjof jjlakes, jjrivers, jjand jjoceans? jj- jjAnswerOne jjwould jjpredict
jjthe jjlarge jjbodies jjof jjwater jjto jjequilibrate jjwith jjatmospheric jjCO_2 jjand jjbecome jjmore
jjacidic.
Sea jjwater jjis jjabout jj______________ jjtimes jjmore jjbasic jjthan jjblack jjcoffee. jj-
jjAnswer1,000
What jjis jjthe jjpH jjrange jjof jjblood? jj- jjAnswer7.35-7.45
For jja jjsolution jjof jjthe jjweak jjacid jjHA, jjwhat jjare jjthe jjformulas jjused jjto jjcalculate jjKa jj=
jj____________ jjand jjpKa jj= jj____________? jj- jjAnswerKa jj= jj[H+][A-] jj/ jj[HA]
pKa jj= jj-log jj[Ka]
The jjpK jjof jjacetic jjacid jjis jjpK jj= jj4.76. jjFor jja jj0.1 jjM jjsolution jjof jjacetic jjacid jjat jja jjpH jj=
jj4.76 jjwhat jjis jjthe jjconcentration jjof jj[H+]? jj- jjAnswer[H+] jj= jj[CH3COO-] jj= jj0.05 jjM. jjFor
jjsolutions jjof jjweak jjacids jjand jjbases jjwith jja jjpH jj= jjpK jjthe jjconcentrations jjof jjH+ jjand
jjOH- jjare jjequal.
Write jjthe jjHenderson-Hasselbalch jjequation. jj- jjAnswerpH jj= jjpKa jj+ jjlog([A-]/[HA])
, Why jjare jjweak jjacids jjand jjbases jjgood jjbuffers jjand jjhow jjdoes jja jjbuffer jjwork? jj-
jjAnswerWeak jjacids jjand jjbases jjonly jjpartially jjdissociate jjinto jjH+ jjand jjconjugate
jjbase. jjThey jjare jjgood jjbuffers jjbecause jjin jjsolution jjthere jjis jja jjpH jj= jjpK jjat jjwhich jjthe
jjweak jjacid jjor jjbase jjis jjonly jj50% jjdissociated jjand jjcould jjdonate jjor jjaccept jjhydrogen
jjions jjif jja jjreaction jjin jjthe jjsolution jjused jjor jjcreated jjmore jjH+. jjBuffers jjwork jjby
jjaccepting jjor jjdonating jjH+, jjwhen jjat jjpH jj= jjpK jjand jjpreventing jjrapid jjchanges jjin jjthe
jjsolution jjpH
What jjare jjthe jjthree jjmajor jjbuffering jjsystems jjused jjin jjour jjbodies? jj-
jjAnswerPhosphate, jjproteins, jjbicarbonate
When jjwe jjexercise jjwe jjproduce jjCO2 jjand jjlactic jjacid jjin jjour jjmuscle jjtissues. jjHow
jjdo jjour jjbodies jjprevent jjwide jjfluctuations jjin jjblood jjpH jjfrom jjexercise? jj- jjAnswerThe
jjbicarbonate jjbuffer jjhelps jjto jjmaintain jja jjconstant jjblood jjpH jjbut jjbecause jjits jjpK jjis
jjover jj1 jjpH jjunit jjfrom jjthe jjblood jjpH jj7.4. jjBecause jjof jjthis jjour jjbodies jjhave jjevolved
jja jjcomplex jjsystem jjto jjprevent jjbuild jjup jjof jjCO2 jjconcentrations jjin jjblood jjby jjexpiring
jjthe jjexcess jjCO2 jjfrom jjour jjlungs jjand jjby jjexcreting jjit jjin jjour jjurine
If jjan jjindividual jjweak jjbond jjcan jjbe jjbroken jjat jjroom jjtemperature, jjhow jjdo jjweak
jjbonds jjwork jjto jjmaintain jjprotein jjand jjDNA jjstructure? jj- jjAnswerWeak jjbonds jjwork jjby
jjstrength jjin jjnumbers. jjThe jjenergy jjto jjbreak jjhundreds jjor jjthousands jjof jjweak jjbonds
jjcan jjexceed jjthe jjenergy jjrequired jjto jjbreak jja jjcovalent jjbond, jjthus jjmany jjweak
jjbonds jjhelp jjmaintain jjprotein jjand jjDNA jjstructure
Ionic jjbonds, jjhydrogen jjbonds, jjand jjvan jjder jjWaal's jjinteractions jjare jjall jjweak jjbonds
jjthat jjform jjby jjattraction jjbetween jjtwo jjatoms jjor jjmolecules. jjWhat jjis jjthe jjname jjof jjthe
jjweak jjforce jjthat jjdoes jjnot jjwork jjby jjattraction? jjDescribe jjwhy. jj- jjAnswerThe jjname jjof
jjthe jjweak jjinteraction jjis jjthe jjhydrophobic jjeffect. jjIt jjworks jjby jjcreating jjmore jjentropy
jjin jjwater jjsolutions. jjAn jjimportant jjexample jjis jjthe jjformation jjof jjcellular jjmembranes
jjbetween jjlipids jjthat jjare jjinsoluble jjin jjwater. jjAggregation jjbetween jjthe jjlong,
jjuncharged jjlipid jjside jjchains jjreleases jjthe jjsurrounding jjwater jjmolecules jjback jjinto
jjbulk jjwater jjincreasing jjthe jjoverall jjentropy jjof jjthe jjsystem
Individual jjweak jjbonds jjare jjapproximately jj__________-fold jjweaker jjthan jjstrong
jjcovalent jjbonds. jj- jjAnswer10
The jjweak jjvan jjder jjWaal's jjforce jjcreates jjits jjown jjattractive jjforce jjbetween jjatoms
jjdue jjto jj_____________ jj_____________ jjformed jjby jjrepulsion jjbetween jjelectrons. jj-
jjAnswerinduced jjdipoles
The jjunusually jjhigh jjsurface jjtension jjproperty jjof jjwater jjthat jjallows jjwater jjstriders jjto
jj"walk" jjon jjwater jjis jjdue jjto jj___________________________________. jj-
jjAnswerhydrogen jjbonding jjnetworks
A jjbuffer jjis jja jj______________ jjreservoir. jj- jjAnswerproton
