the pentose phosphate pathway Flashcards
what is the pentose phosphate pathway also known as
the hexose monophosphate pathway
what does the pentose phosphate pathway produce in the cytosol
NADPH
pentose phosphates
what does the pentose phosphate pathway not produce
ATP
how many phases is the pentose phosphate pathway divided into
two
name the two phases that the pentose phosphate pathway is divided into
oxidative phase
non-oxidative phase
describe the oxidative phase within the pentose phosphate phase
produces NADPH and ribulose-5-phosphate and is irreversible
describe the non-oxidative phase within the pentose phosphate phase
recycles surplus pentose phosphates back to glycolysis and is reversible
how is NADPH used during the oxidative phase in the pentose phosphate pathway
used as a reducing equivalent in the synthesis of fatty acids, cholesterol and other steriods
eg in the liver, aderenal glands and reproductive tissues
also used to maintain antioxidant defence systems
can be used to generate oxygen free radical
what is glucose-6-phosphate dehydrogenase
a rate limiting enzyme which is regulated by the availability of NADP+
what is the ratio of NADPH : NADP+ normally
roughly 100
what increases the enzyme activity of glucose-6-phosphate dehydrogenase
an increase in the consumption of NADPH which increases the availability of NADP+ which then increases the enzyme activity
what is glucose-6-phosphate dehydrogenase deficiency
the most common inborn error of metabolism
the G6PD gene is X-linked
causes acute haemolytic anaemia during oxidative stress
what is ribose-5-phospahte used in
nucleic acid synthesis
