Eric Niederhoffer SIU-SOM What is the role of the pentose phosphate pathway?
Eric Niederhoffer
SIU-SOM
What is the role of the pentose phosphate pathway?
Overview
• NADPH productionGlutathione reduction (E), fatty acid/cholesterol synthesis (L)
• Glycolytic intermediatesFructose-6-phosphate, glyceraldehyde-3-phosphate
• Ribose-5-phosphateNucleotide synthesis (nucleated cells)
Glycolysis and Pentose Phosphate Pathways
PPP
NADPH
6PG
3-7 C metabolites(R5P, F6P, G3P)
G6PDHlactonase6PGDH
CO2
NADP+ + H+
GSH
GSSGGR
GP
H2O2 H2O
Glc
Pyr
G6P
1,3-BPG
3PG
HK
PGI
PK
F6P
DHAP + G3P
PFK
aldolaseF16BP
2PG
PEP
PGK
PGM
enolase
G3PDH
Glycolysis
Oxidative Phase
Glucose G6PHK
F6PPGI
G6PDH
6PGL
NADPHNADP+
lactonase
6PG
•FA/cholesterol synthesis•RBC ox stress
CO2
6PGDH
Ru5P
NADPHNADP+
Non-oxidative Phase
Ru5P
Xu5P
RuP3E
R5P
R5PI
TK
S7P
G3PTA
E4P
F6P
TK
F6P
G3P
Glycolysis Nucleotides
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?