What is the role of the pentose phosphate pathway?
Eric Niederhoffer
SIU-SOM
Overview
• NADPH production
Glutathione reduction (E), fatty acid/cholesterol synthesis (L)
• Glycolytic intermediates
Fructose-6-phosphate, glyceraldehyde-3-phosphate
• Ribose-5-phosphate
Nucleotide synthesis (nucleated cells)
Glycolysis and Pentose Phosphate
HO
GSH
Pathways
GP
HK
2
Glc
G6P
NADP+ + H+
PGI
PFK
aldolase
DHAP +
NADPH
F16BP
G3P
G3PDH
1,3-BPG
PGK
3PG
G6PDH
lactonase
6PGDH
CO2
6PG
PPP
PGM
2PG
enolase
PEP
PK
Pyr
H2O
GSSG
GR
F6P
Glycolysis
2
3-7 C metabolites
(R5P, F6P, G3P)
Oxidative Phase
HK
Glucose
G6P
PGI
F6P
NADP+
NADPH
G6PDH
6PGL
lactonase
•FA/cholesterol synthesis
•RBC ox stress
6PG
6PGDH
CO2
Ru5P
NADP+
NADPH
Non-oxidative Phase
Ru5P
RuP3E
R5PI
F6P
G3P
Glycolysis
Xu5P
TK
E4P
F6P
S7P
TA
G3P
R5P
Nucleotides
TK
Review Questions
• What are the main functions of the
pentose phosphate pathway?
• Which enzymes produce NADPH?
• Which intermediates can feed back into
the glycolytic pathway?