Pentose Phosphate Pathway Flashcards
what are the 2 goals of the PPP
to generate reducing powers (NADPH)
and to generate ribose
what is the currency of reducing power for most reductive biosynthetic reactions
NADPH
what does the PPP generate?
ribose 5 phosphate
where are the reactions of the PPP carried out ?
in the cytosol
describe the first phase of PPP
the oxidative phase, glucose gets oxidized and NADP+ gets reduced to NADPH. 3 enzymes, 2 NADPH generated
describe the second phase of PPP
the non oxidative phase
ribulose 5 phosphate is converted to ribose 5 phosphate.
NO NADPH formed.
lots of interconversions of carbon happening
does the cell require NADPH more or Ribose 5 phosphate
NADPH
what happens to excess ribose 5 phosphate in PPP
it can go into glycolysis and be converted to intermediates by the enzymes Transaldolase and Transketolase
what is the PPP primarily regulated by
levels of NADP+ in the cytosol
which enzymes compete to bind to glucose 6 phosphate dehydrogenase
NADPH and NADP+
if the need for NADPH is low, what happens in the PPP
pathway favours glycolysis
where does the PPP occur (tissues?)
usually in the liver
