Pentose Phosphate pathway Flashcards
for glucose metabolism, if ATP is not needed, what would happen
either glycogen synthesis or the pentose phosphate pathway
what is the first molecule of the pentose phosphate pathway
glucose-6-phosphate
what is the final product of the pentose phosphate pathway
ribose-5-phosphate
alternative names for the pentose phosphate pathway
hexose monophosphate shunt
hexose monophosphate pathway
functions of the HMP pathway
results in the synthesis of NADPH and ribose sugars (ribose-5-phosphate)
why is the synthesis of ribose 5 phosphate important
it is a major substrate in many lipid metabolic pathway
NADH vs NADPH
NADH: generated during catabolism
NADPH: used mainly for anabolism
not interconvertible
what is the committed step of the pentose phosphate pathway
G6P dehydrogenase reaction
where does the pentose phosphate pathway occur
in the cytosol of tissues that are active in biosynthesis - liver
what happens in G6P dehydrogenase deficiency
deficiency in HMP pathway
generally still have enough activity for normal function
sensitive to oxidative damage
why are erythrocytes particularly sensitive to oxidative damage in G6P deficiency
they carry a lot of oxygen and are more likely to produce ROS
what is glutathione
what is its role
GSH is a thiol tripeptide (Glu/Cys-SH/Gly)
reducing agent found in most cells that keeps proteins with essential cysteine groups in the reduced state
what is the major function of GSH in RBCs
eliminates H2O2 and other reactive oxygen metabolites
gets oxidised by glutathione peroxidase to GS-SG
how is reduced GSH regenerated
which enzyme does this
NADPH required to convert oxidised glutathione to reduced glutathione catalysed by glutathione reductase
examples of stressful situations for patients lacking G6PD
sensitive to oxidising substances
sulpha drugs
antimalarials
infectious agents
fava beans (wtf)
