Glycolysis
Prof. Sylvester L.B. Kajuna
Hubert Kairuki Memorial University
April, 2017
, 6 CH OPO 2
2 3
5 O
H H
H
4 H 1
OH
OH OH
3 2
H OH
glucose-6-phosphate
Glycolysis takes place in the cytosol of
cells.
Glucose enters the Glycolysis pathway by
conversion to glucose-6-phosphate.
Initially there is energy input corresponding
to cleavage of two ~P bonds of ATP.
, 6 CH 2 O H 6 CH O PO 2
2 3
ATP ADP
5 O 5 O
H H H H
H H
4 1 4 H 1
OH H OH
M g 2+
OH OH OH OH
3 2 3 2
H OH H ex ok inase H OH
glucose glucose -6 -ph osp hate
1. Hexokinase catalyzes:
Glucose + ATP glucose-6-P + ADP
The reaction involves nucleophilic attack of
the C6 hydroxyl O of glucose on P of the
terminal phosphate of ATP.
ATP binds to the enzyme as a complex with
Mg++.
, NH2
ATP N
N
adenosine triphosphate
O O O N N
O P O P O P O CH2 adenine
O
O
O
O
H H
H H
OH OH
ribose
Mg++ interacts with negatively charged
phosphate oxygen atoms, providing charge
compensation & promoting a favorable
conformation of ATP at the active site of the
Hexokinase enzyme.
Prof. Sylvester L.B. Kajuna
Hubert Kairuki Memorial University
April, 2017
, 6 CH OPO 2
2 3
5 O
H H
H
4 H 1
OH
OH OH
3 2
H OH
glucose-6-phosphate
Glycolysis takes place in the cytosol of
cells.
Glucose enters the Glycolysis pathway by
conversion to glucose-6-phosphate.
Initially there is energy input corresponding
to cleavage of two ~P bonds of ATP.
, 6 CH 2 O H 6 CH O PO 2
2 3
ATP ADP
5 O 5 O
H H H H
H H
4 1 4 H 1
OH H OH
M g 2+
OH OH OH OH
3 2 3 2
H OH H ex ok inase H OH
glucose glucose -6 -ph osp hate
1. Hexokinase catalyzes:
Glucose + ATP glucose-6-P + ADP
The reaction involves nucleophilic attack of
the C6 hydroxyl O of glucose on P of the
terminal phosphate of ATP.
ATP binds to the enzyme as a complex with
Mg++.
, NH2
ATP N
N
adenosine triphosphate
O O O N N
O P O P O P O CH2 adenine
O
O
O
O
H H
H H
OH OH
ribose
Mg++ interacts with negatively charged
phosphate oxygen atoms, providing charge
compensation & promoting a favorable
conformation of ATP at the active site of the
Hexokinase enzyme.
