Conversion of Pyurvate Ion to Acetyl CoA
Dr. Gergens - Mesa College
The decarboxylation and oxidation of pyruvate to produce acetyl CoA:
O
C
CH3
O
C
NAD+
O-
+
NADH
O
CH3 C
H-S-CoA
pyruvate ion
Coenzyme A
dehydrogenase
complex
+
S CoA
CO2
acetyl coenzyme A
Pyruvate is decarboxylated, which liberates a molecule of CO 2 . It is also oxidized, and hydride anion, H:– , that is
removed is accepted by NAD+ .
Finally, the remaining acetyl group, CH3 CO2 – , is linked to coenzyme A by a
thioester bond. The pyruvate dehydrogenase complex that carries out this reaction is actually a cluster of three
enzymes and five coenzymes.
Acetyl coenzyme A is a central character in cellular metabolism. The principle function of acetyl CoA in energygenerating pathways is to carry the acetyl group to the citric acid cycle (the Krebs Cycle), where it will be used
to produce large amounts of ATP energy.
Lipids
Polysaccharides
Proteins
monosaccharides
Fatty Acids
Amino Acids
GLYCOLYSIS
Acetyl CoA
Fatty Acids
CITRIC ACID CYCLE
Cholesterol
Ketone bodies
Triglycerides
CO2
+ H2O
ATP
Bile salts
Phospholipids
Steroids
NH2
CH3
O
C S
acetate
CH2 CH2
O
N C
H
N
CH3
O
C CH2 O
OH CH3
P
H
C
O-
O
P
O
CH2
O-
O
P
O-
N
O
O
acetyl coenzyme A
N
O
OH
O-
N