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OVERVIEW OF
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MOUTH
STOMACH
SMALL INTESTINE
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CARBOHYDRATES Glucose
Monosaccharides
PROTEIS AD FATTY ACIDS A!ino acids
FATS AD OI"S Gl#cerol
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So!e reac$ions occur in $he c#$osolo% cells and so!e in cellular!i$ochondria
S!all !olecules %ro! di&es$ion are%ur$her o'idi(ed durin& $his s$a&e
Pri!ar# )roduc$s include $*o+car,on ace$#l uni$s and $he reducedcoen(#!e ADH-
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Occurs inside $he !i$ochondria
Ace$#l &rou)s are o'idi(ed $o
)roduce CO.and ener CO.$ha$ is e'haled as )ar$ o%
$he ,rea$hin& )rocess co!es)ri!aril# %ro! $his s$a&e
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Occurs inside $he !i$ochondria
ADH and FADH. su))l# $he /%uel0
needed %or $he )roduc$ion o% ATP!olecules1 $he )ri!ar# enercarriers in !e$a,olic )a$h*a#s
Molecular O.1 inhaled in ,rea$hin&1is con2er$ed $o H.O in $his s$a&e
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Co!!on Me$a,olic Pa$h*a# Su! $o$al o% $he ,ioche!ical reac$ions o%
$he ci$ric acid c#cle1 $he elec$ron $rans)or$
chain1 and o'ida$i2e )hos)hor#la$ion
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The series o% ,ioche!ical reac$ions in*hich $he ace$#l )or$ion o% ace$#l CoAis o'idi(ed $o car,on dio'ide and $he
reduced coen(#!e FADH. and ADHare )roduced-
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a!ed a%$er i$s disco2erer ,# Hans Adol%3re,s1 and as $he $ricar,o'#lic acid c#cle1in re%erence $o $he $hree car,o'#la$e
&rou)s )resen$ in ci$ric acid c#cle-
O'ida$ion 4 )roduces ADH or FADH. Decar,o'#la$ion 4 car,on chain is
shor$ened ,# $he re!o2al o% a car,ona$o! as a CO. !olecule
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Ace$#l CoA1 *hich carries $he$*o+car,on de&ra$ion )roduc$
o% car,oh#dra$es1 %a$s1 and)ro$eins1 en$er $he c#cle ,#co!,inin& *i$h $he %our+car,on
5e$o dicar,o'#la$e s)ecieso'aloace$a$e-
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This resul$s in $he $rans%er o% $he
ace$#l &rou) %ro! coen(#!e A $oo'aloace$a$e1 )roducin& $he C6 ci$ra$es)ecies and %ree coen(#!e A-
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Ci$ra$e is con2er$ed $o i$s lesss#!!e$rical iso!er isoci$ra$e in aniso!era$ion )rocess $ha$ in2ol2es a
deh#dra$ion %ollo*ed ,# h#dra$ion1,o$h ca$al#(ed ,# $he en(#!eaconi$ase- The ne$ resul$ o% $hese
reac$ion is $ha$ $he 4OH &rou) %ro!ci$ra$e is !o2ed $o a di7eren$ car,ona$o!-
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This s$e) in2ol2es o'ida$ion+reduc$ionand decar,o'#la$ion- The reac$an$s area AD8 !olecules and isoci$ra$e- The
reac$ion1 ca$al#(ed ,# isoci$ra$edeh#dro&enase1 is co!)le'-
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Isoci$ra$e is o'idi(ed $o a 5e$oneO9A"OS:CCIATE
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One h#dro&en and $*o elec$rons are$rans%erred $o AD8$o %or! ADH; $here!ainin& h#dro&en ion
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The o'alosuccina$e re!ains ,ound $oen(#!e and under&oesdecar,o'#la$ion ?+5e$o&lu$ara$e
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This second redo' reac$ion o%$he c#cle in2ol2es one !oleculeeach o% AD81 CoA+SH1 and ?+5e$o&lu$ara$e- The ca$al#s$ is a
$hree+en(#!e s#s$e! called$he ?+5e$o&lu$ara$edeh#dro&enase co!)le'-
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T*o reac$an$ !olecules are in2ol2edin $his s$e) 4 a Pi
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In $he rs$ s$e)1 succin#l CoA iscon2er$ed $o succin#l )hos)ha$e < ahi&h+ener )hos)ha$e co!)ound=;CoA+SH is a )roduc$ o% $his chan&e-The )hos)hor#l &rou) )resen$ insuccin#l )hos)ha$e is $hen
$rans%erred $o GDP; $he )roduc$s o%$his chan&e are GTP and succina$e-
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This is $he $hird redo' reac$ion o% $hec#cle- The en(#!e in2ol2ed issuccina$e deh#dro&enase1 and $he
o'idi(in& a&en$ is FAD ra$her $hanAD8- T*o h#dro&en a$o!s arere!o2ed %ro! $he succina$e $o )roduce
%u!ara$e1 a C@s)ecies *i$h a $ransdou,le ,ond- FAD is reduced $o FADH.
in $he )rocess-
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The en(#!e%u!araseca$al#(es $he addi$ion o%
*a$er $o $he dou,le ,ond o%%u!ara$e- The en(#!e iss$ereos)ecic1 so onl# $he "
iso!er o% $he )roduc$ !ala$eis )roduced-
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In $he %our$h o'ida$ion+reduc$ion reac$iono% $he c#cle1 a !olecule o% AD8 reac$s*i$h !ala$e1 )ic5in& u) $*o h#dro&en
a$o!s *i$h $heir associa$ed ener $o%or! ADH 8 H8- The needed en(#!e is!ala$e deh#dro&enase- The )roduc$ o%$his reac$ion is re&enera$ed o'aloace$a$e1
*hich can co!,ine *i$h ano$her !oleculeo% ace$#l CoA1 and $he c#cle ,e&in a&ain-
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TO HELP BETTER UNDERSTAND
THE CITRIC ACID CYCLE
THE VIDEO WI"" E9P"AI STEP BY STEP THE CITRIC CID CYC"E-
IT WI"" E9P"AI EVERY REACTIO THAT TOO3 P"ACE I EVERYSTEP-
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