DR. SIDDHARTH DUTTA (PGT)
CARBOHYDRATE
METABOLISM
Carbohydrate Concept Map
Carbohydrate Metabolism
The Major Pathways:
 Glycolysis
 Citric Acid Cycle
 Gluconeogenesis
 Glycogenesis
 Glycogenolysis
 Hexose monophosphate shunt
 Uronic acid pathway
 Galactose metabolism
 Fructose metabolism
 Amino sugar & mucopolysaccharide metabolism
GLYCOLYSIS
GYLCOLYSIS
(C6H12O6) 2 x (CH3-CO-COOH)
Krebs Cycle
Fermentation
Aerobic
condition
Anaerobic
condition
CARBOHYDRATEMETABOLISM
CARBOHYDRATEMETABOLISM
6C
6C
6C
3C 3C
6C
CARBOHYDRATEMETABOLISM
6C
CARBOHYDRATEMETABOLISM
Pi
2H
X 2
3C 3C
H2O
CARBOHYDRATEMETABOLISM
2nd Phase
ENERGY IS
PRODUCED
CARBOHYDRATEMETABOLISM
2ATP (-)
2ATP (+) X 2
2ATP
NET OUTPUT
X 2
[NADH + H+] X 2
6ATP
0ATP
Aerobic
condition
Anaerobic
condition(when in mitochondria)
Krebs Cycle
CoA
CO2
NAD
[NADH + H+]
Acetyl-CoA 2C
CARBOHYDRATEMETABOLISM
Pyruvate dehydrogenase
(PDH)
Fumerase
NAD+
Acetyl-CoA 2C
CARBOHYDRATEMETABOLISM
[NADH + H+]
Citrate Synthase
CoA
Isocitrate
dehydrogenase
FADH2
FAD
Krebs Cycle
CoA
H2O
Succinate
dehydrogenase
Alphaketoglutarate
dehydrogenase
Succinyl CoA synthase
Malate
dehydrogenase
Aconitase
Gluconeogenesis
Gluconeogenesis
CARBOHYDRATE
ENZYMES
BREAKDOWN
GLUCOSE
FAT
AMINO ACIDS
PYRUVATE
(Non Carb Sources)
CARBOHYDRATEMETABOLISM
GLYCOGEN
Blood Glucose Levels
100-200 MG/DL
FASTING
CARBOHYDRATEMETABOLISM
SITES OF GLUCONEOGENESIS
LIVER
50-60%
KIDNEY
40%
INTESTINE
MINOR
CARBOHYDRATEMETABOLISM
BLOOD
GLUCOSE (6C)
PYRUVATE
(3C)
PYRUVATE
GLUCOSE
3 irreversible
reactions
GLYCOLYSIS
10 REACTIONS
SPECIFIC ENZYMES can
reverse these
reactions under special
circumstances like
FASTING
CARBOHYDRATEMETABOLISM
1
2
3
CARBOHYDRATEMETABOLISM
OXALOACETATE
Phosphoenol-pyruvate
Carboxylase CO2
GTP
Fructose
1,6 Bisphosphate
Phosphofructokinase
Pi ATP
ADP
REVERSIBLE REACTIONS
Mitochondria
OXALOACETATE
CO2
ATP
Pyruvate
carboxylase
CARBOHYDRATEMETABOLISM
ATP
ADP
Hexokinase
REVERSIBLE REACTION
Pi
Glucose-6-phosphate
Propionate
Glycerol
CARBOHYDRATEMETABOLISM
Succinyl CoA
KREBS CYCLE
Lactate
Lactate
Dehydrogenase
Reversal process continues as explained before.
Glycerol 3-phosphate
1
23
4
5 O O
1
2
34
5
6
6
P
P
Glucose 6-phosphate Fructose 6-phosphate
Carbohydrate Metabolism

Carbohydrate Metabolism