Biochemistry
, GLYCOLYSIS
Glycolysis is the process in which
glucose is broken down to produce
energy.
It produces two molecules of
pyruvate,
ATP , NADH and water .
CSMa2OG + 2NAD" + CADP + 2P 2
pyruvic acid CHz(CO) COOM
,
+ 2 ATP + 2 NADH + 24
+
steps with enzymes Hexokinase ,
phosphoglucose Isomerase , phosphofructokinase, aldolase , triosephosphate isomerase,
glyceraldehyde 3 phosphate dehydrogenase, phosphoglycerate Kinase ,
phosphoglycerate mutase , enolase ,
pyruvate kinase .
STEP 1 : HEXOKINASE STEP 2 : PHOSPHOGLUCOSE ISOMERASE
H H ON CH20H
H
C CO
HC OH OP
I
HC
hexokinase HC Of
POHOMO
O 0 + HOCH
TH
-
↑ H
ATP- & ADP H &
Hom
HOCH
HO
OH H
OH H0 co
non
HC
H
D Glucose
OH
Glucose
H
6
OH
phosphate
H OH
CH20P
3 CM20P
Fructose
ON
G
H
phosphate
Glucose 6 phosphate phosphoglucose
Conversion of D into 6 phosphate.
glucose glucose isomerase
Phosphorylation ,
adds a phosphate group to a molecule Conversion of
glucose 6 phosphate to fructose G phosphate.
derived from ATP ATP has been Atomic
. consumed. Isomerisation reaction.
Rearrangement of the c o bond to
magnesium is used to help shield the negative charges transform the G membered
ring into 5 membered
ring .
from the phosphate groups on the ATP molecule. The s membered ring opens and then closes for
making the first
prevents passage carbon becomes external
negative charge of the phosphate of the to the ring
. From
C1 to C2 ,
forming a
sugar phosphate through the plasma membrane , trapping ketose from an aldose
sugar.
inside the cell.
glucose
STEP 3 : PHOSPHOFRUCTOKINASE STEP 4: ALDOLASE
H20P
non
POH CH,OP
CH20P
2 O
-
POH phosphofructokinase
POH2(&(420P O Aldolase
Ho
,ORO + ATP
KEY ENZYME
H
HHO
on
+ ADP + H
HHHO OM
H
OH H
RATE LIMITING
Fructose 2 , 6 biphosphate OH H
Fructose
OH
6
H
phosphate Fructose 1, 6 bisphosphate
Dihydroxyacetone Glyceraldelese
3 phosphate
conversion of fructose G phosphate into fructose 1 ,6 biphosphate Aldolase splits fructose 2. ,6 biphosphate into two
sugars that are isomers
Phosphorylation with ATP Similar to first reaction
. . of each other DHAP and GAP Cleaves of FBP to
. .
yield two 3 Carbon
molecules .
Only GAP can proceed immediately through glycolysis .
, STEP5: TRIOSEPHOSPHATE ISOMERASE STEPG: GLYCERALDEHYDE 3-PHOSPHATE DEMYDROGENASE
Triose phosphate
NO O M O OP
Glyceraldehyde3 phosphate
CM20N isomerase C C dehydrogenase C
CO M C of H C OM + NADt + Pi H COM NADH + H
CH ,0P CM>OP CH20P CM20P
Glyceraldehyde
2 ,3
biphosphoglycerate
Dihydroxyacetone 3 phosphate (GAP) Glyceraldehyde
phosphate (DHAP) 3 phosphate
Conversion of DHAP to GAP GAP is removed used in the next
. GAPDH dehydrogenates and adds
inorganic phosphate to GAP
step of glycolysis . GAP is the only molecule that continues in the into 1 .3
bisphosphoglycerate . GAP is oxidized by the coenzyme
glycolytic pathway .
DMAP is
reorganizes by triosephosphate NAD .
Phosphorylation by the addition of a free phosphate group .
isomerase into GAP , to continue in
glycolysis . Two 3 carbon The
enzyme GAPDH holds the molecule in a conformation , it
molecules , but glucose is not converted into
pyruvate . allow the NAD molecule to pull a
hydragen off the GAP
converting NAD to NADM The .
phosphate group altacks the GAP
and releases it from the enzyme to yield 2 3 bisphoglycerate, ,
NADH and HT
STEP7 : PHOSPHOGLYCERATE KINASE STEP8 : PHOSPHOGLYCERATE MUTASE
O OP o o O O O O
C
Phosphoglycerate C C
phosphoglycerate C
Kinase mutase
HC + ATP HC Of H C OP
HC OH + ADP OM
CH2OP CH20P CH20P CHION
1 ,3
bisphosphoglycerate 3
phosphoglycerate
3 phosphoglycerate 2 phosphoglycerate
2,3
bisphosphoglycerate is converted to 3
phosphoglycerate by the Rearrangement of the position of the phosphate group on the
enzyme PGK Loss
.
of phosphate group from the starting material. The 3 phosphoglycerate molecule ,
making it 2
phosphoglycerate.
phosphate is transferred to a molecule of ADP that yields the first Catalyzed by enzyme PGM .
A mutase is an
enzyme that
catalyzes
molecule of ATP Two molecules of because two the transfer of functional group from position molecule
. 1.3
bisphoglycerate ,
a one on a
carbon products from phosphate group to the 2 position of the
3
stage 1 of glycolysis ,
two molecules of Appare to another Addition . of
Synthesize .
Cancellation of the first two molecules of ATP that were 3
phosphoglycerate by removing it from 3 position yielding
, ,
used , net of original phosphorylated
O ATP. 2
phosphoglycerate .
Enzyme restored to its
state Free .
energy of hydrolysis.
STEP9: ENOLASE STEP 10 : PYRUVATE KINASE
0 0 00 o 0 00
C Enolase C C
C Pyruvate Kinase
HC OP Cop + M20 C O + ATP
C OP + ADP + Ht
CHION (PEP hydratase) CM2 CHz
CH2
2
phosphoglycerate phosphoendpyruvate Pyruvate
Phosphoendpyruvate
, I
This step involves the conversion of 2 Conversion of phosphoend pyruvate into
phosphoglycerate to pyruvate with the help of
phosphoenopyruvate (PEP) .
Enzyme enolase. Removes a water
group pyruvate kinase. Transfer of a phosphate group. The phosphate
or
dehydrates 2
phosphoglycerate. High energy end phosphate group attached to the 2'c of the PEP is transferred to a molecule of
linkage .
ADP ,
yielding ATP .
2 PEP molecules produce 2ATP
.
strate
Level
Phosphorylan M
C
O
glyceraldehyde
HC Or
Oxidation of primary addition product , forms a thioacetal high energy
3 phosphate
CH20P
covanta
non Enzyme S
Cysteineside covalent banda
thioester .
By substitution a
high energy phosphate can be formed NADt
(2,3 bisphosphoglycerate) and ATP ENZYME S Glyceraldehyde3 phosphate
HC Of dehydrogenase
O HC ON
E
CM20P
Transformation of oxidation energy in
phosphorylation energy :
# + H
+ Oxidation of GAP 2e + .
M
+
form NADH
store
energy
CHO to COOH , NADT to NADH HT and ADP to ATP
SHighEnergyon
+ ENZyME se
HC Of
CH20P O
Esult
Glyclys of O
HOP
O
OH
2 molecules of ATP and 2 molecules of NADH. Ho & 2 ,3
bisphosphoglycerate High energy acyl anhydride band
HC Of
CM20P PPO
ADENINE
Phosphoglycerate Kinase
RIBOSE ADP
T
High energy band transferred
Reg 3 Phosphofructokinase (PFK)
Glydimme
ADENINE
PPP O
HO O RIBOSE
III
C
Inhibition by Ht : in Step 1,3 and 6
. H C of
CH2OP 3
phosphoglycerate
Inhibition
by citrate : the first product in the citrate cycle inhibits
PFK (feedback inhibition)
Inhibition by ATP : feedback (cell already supplied with energy High energy charge)
Activation by feedback (cell
AMP : needs
energy Low
energy charge
Disproportionation
2ADP ATP + AMP Ampactivates phosphofructokinase (step 3) stimulates also ,
glycolysis
Adenylate Kinase
ergyage
Or adenylate energy charge .
Indicates the
energy status of a cell It
. depends on the concentrations of ATP , ADP and AMP .
Range
between 07. and 0 . 99.
ATP + 2 ADP
Energy ATP + ADD + AMP
, GLYCOLYSIS
Glycolysis is the process in which
glucose is broken down to produce
energy.
It produces two molecules of
pyruvate,
ATP , NADH and water .
CSMa2OG + 2NAD" + CADP + 2P 2
pyruvic acid CHz(CO) COOM
,
+ 2 ATP + 2 NADH + 24
+
steps with enzymes Hexokinase ,
phosphoglucose Isomerase , phosphofructokinase, aldolase , triosephosphate isomerase,
glyceraldehyde 3 phosphate dehydrogenase, phosphoglycerate Kinase ,
phosphoglycerate mutase , enolase ,
pyruvate kinase .
STEP 1 : HEXOKINASE STEP 2 : PHOSPHOGLUCOSE ISOMERASE
H H ON CH20H
H
C CO
HC OH OP
I
HC
hexokinase HC Of
POHOMO
O 0 + HOCH
TH
-
↑ H
ATP- & ADP H &
Hom
HOCH
HO
OH H
OH H0 co
non
HC
H
D Glucose
OH
Glucose
H
6
OH
phosphate
H OH
CH20P
3 CM20P
Fructose
ON
G
H
phosphate
Glucose 6 phosphate phosphoglucose
Conversion of D into 6 phosphate.
glucose glucose isomerase
Phosphorylation ,
adds a phosphate group to a molecule Conversion of
glucose 6 phosphate to fructose G phosphate.
derived from ATP ATP has been Atomic
. consumed. Isomerisation reaction.
Rearrangement of the c o bond to
magnesium is used to help shield the negative charges transform the G membered
ring into 5 membered
ring .
from the phosphate groups on the ATP molecule. The s membered ring opens and then closes for
making the first
prevents passage carbon becomes external
negative charge of the phosphate of the to the ring
. From
C1 to C2 ,
forming a
sugar phosphate through the plasma membrane , trapping ketose from an aldose
sugar.
inside the cell.
glucose
STEP 3 : PHOSPHOFRUCTOKINASE STEP 4: ALDOLASE
H20P
non
POH CH,OP
CH20P
2 O
-
POH phosphofructokinase
POH2(&(420P O Aldolase
Ho
,ORO + ATP
KEY ENZYME
H
HHO
on
+ ADP + H
HHHO OM
H
OH H
RATE LIMITING
Fructose 2 , 6 biphosphate OH H
Fructose
OH
6
H
phosphate Fructose 1, 6 bisphosphate
Dihydroxyacetone Glyceraldelese
3 phosphate
conversion of fructose G phosphate into fructose 1 ,6 biphosphate Aldolase splits fructose 2. ,6 biphosphate into two
sugars that are isomers
Phosphorylation with ATP Similar to first reaction
. . of each other DHAP and GAP Cleaves of FBP to
. .
yield two 3 Carbon
molecules .
Only GAP can proceed immediately through glycolysis .
, STEP5: TRIOSEPHOSPHATE ISOMERASE STEPG: GLYCERALDEHYDE 3-PHOSPHATE DEMYDROGENASE
Triose phosphate
NO O M O OP
Glyceraldehyde3 phosphate
CM20N isomerase C C dehydrogenase C
CO M C of H C OM + NADt + Pi H COM NADH + H
CH ,0P CM>OP CH20P CM20P
Glyceraldehyde
2 ,3
biphosphoglycerate
Dihydroxyacetone 3 phosphate (GAP) Glyceraldehyde
phosphate (DHAP) 3 phosphate
Conversion of DHAP to GAP GAP is removed used in the next
. GAPDH dehydrogenates and adds
inorganic phosphate to GAP
step of glycolysis . GAP is the only molecule that continues in the into 1 .3
bisphosphoglycerate . GAP is oxidized by the coenzyme
glycolytic pathway .
DMAP is
reorganizes by triosephosphate NAD .
Phosphorylation by the addition of a free phosphate group .
isomerase into GAP , to continue in
glycolysis . Two 3 carbon The
enzyme GAPDH holds the molecule in a conformation , it
molecules , but glucose is not converted into
pyruvate . allow the NAD molecule to pull a
hydragen off the GAP
converting NAD to NADM The .
phosphate group altacks the GAP
and releases it from the enzyme to yield 2 3 bisphoglycerate, ,
NADH and HT
STEP7 : PHOSPHOGLYCERATE KINASE STEP8 : PHOSPHOGLYCERATE MUTASE
O OP o o O O O O
C
Phosphoglycerate C C
phosphoglycerate C
Kinase mutase
HC + ATP HC Of H C OP
HC OH + ADP OM
CH2OP CH20P CH20P CHION
1 ,3
bisphosphoglycerate 3
phosphoglycerate
3 phosphoglycerate 2 phosphoglycerate
2,3
bisphosphoglycerate is converted to 3
phosphoglycerate by the Rearrangement of the position of the phosphate group on the
enzyme PGK Loss
.
of phosphate group from the starting material. The 3 phosphoglycerate molecule ,
making it 2
phosphoglycerate.
phosphate is transferred to a molecule of ADP that yields the first Catalyzed by enzyme PGM .
A mutase is an
enzyme that
catalyzes
molecule of ATP Two molecules of because two the transfer of functional group from position molecule
. 1.3
bisphoglycerate ,
a one on a
carbon products from phosphate group to the 2 position of the
3
stage 1 of glycolysis ,
two molecules of Appare to another Addition . of
Synthesize .
Cancellation of the first two molecules of ATP that were 3
phosphoglycerate by removing it from 3 position yielding
, ,
used , net of original phosphorylated
O ATP. 2
phosphoglycerate .
Enzyme restored to its
state Free .
energy of hydrolysis.
STEP9: ENOLASE STEP 10 : PYRUVATE KINASE
0 0 00 o 0 00
C Enolase C C
C Pyruvate Kinase
HC OP Cop + M20 C O + ATP
C OP + ADP + Ht
CHION (PEP hydratase) CM2 CHz
CH2
2
phosphoglycerate phosphoendpyruvate Pyruvate
Phosphoendpyruvate
, I
This step involves the conversion of 2 Conversion of phosphoend pyruvate into
phosphoglycerate to pyruvate with the help of
phosphoenopyruvate (PEP) .
Enzyme enolase. Removes a water
group pyruvate kinase. Transfer of a phosphate group. The phosphate
or
dehydrates 2
phosphoglycerate. High energy end phosphate group attached to the 2'c of the PEP is transferred to a molecule of
linkage .
ADP ,
yielding ATP .
2 PEP molecules produce 2ATP
.
strate
Level
Phosphorylan M
C
O
glyceraldehyde
HC Or
Oxidation of primary addition product , forms a thioacetal high energy
3 phosphate
CH20P
covanta
non Enzyme S
Cysteineside covalent banda
thioester .
By substitution a
high energy phosphate can be formed NADt
(2,3 bisphosphoglycerate) and ATP ENZYME S Glyceraldehyde3 phosphate
HC Of dehydrogenase
O HC ON
E
CM20P
Transformation of oxidation energy in
phosphorylation energy :
# + H
+ Oxidation of GAP 2e + .
M
+
form NADH
store
energy
CHO to COOH , NADT to NADH HT and ADP to ATP
SHighEnergyon
+ ENZyME se
HC Of
CH20P O
Esult
Glyclys of O
HOP
O
OH
2 molecules of ATP and 2 molecules of NADH. Ho & 2 ,3
bisphosphoglycerate High energy acyl anhydride band
HC Of
CM20P PPO
ADENINE
Phosphoglycerate Kinase
RIBOSE ADP
T
High energy band transferred
Reg 3 Phosphofructokinase (PFK)
Glydimme
ADENINE
PPP O
HO O RIBOSE
III
C
Inhibition by Ht : in Step 1,3 and 6
. H C of
CH2OP 3
phosphoglycerate
Inhibition
by citrate : the first product in the citrate cycle inhibits
PFK (feedback inhibition)
Inhibition by ATP : feedback (cell already supplied with energy High energy charge)
Activation by feedback (cell
AMP : needs
energy Low
energy charge
Disproportionation
2ADP ATP + AMP Ampactivates phosphofructokinase (step 3) stimulates also ,
glycolysis
Adenylate Kinase
ergyage
Or adenylate energy charge .
Indicates the
energy status of a cell It
. depends on the concentrations of ATP , ADP and AMP .
Range
between 07. and 0 . 99.
ATP + 2 ADP
Energy ATP + ADD + AMP
