gluconeogenesis Flashcards
(23 cards)
gluconeogenesis
forms glucose
where does gluconeogen. take place
90% in the liver and 10% in the kidney
what steps are the same with glycolysis
hexokinase, pfk1, PK
- glucose 6 phosphatase
- fructose 1,6 bisphosphatase
- pep carboxykinase
what enzymes do you need to bypass pyruvate kinase
pyruvate carboxylase and phosphophenolpyruvate carboxykinase
what does pyruvate carboxylase catalyze
biotin dependent conversion of pyruvate to oxaloacetate in the mito matrix
pepck function
uses GTP to covert oxoalocacetate to PEP by phosphorylation
energy cost from pyruvate
2 atp
2 gtp= atp equivalent
=2 atp
6 net atp
2 nadh used
glucokinase
hexokinase isozyme of glcolysis in the liver
what is glucokinase bypassed by
glucose 6 phosphatase
what is importnt about the liver and its relation to glucokinase
huge reservoir or buffer for glucose so that is why glucpkinase never achieve equil
location of gluconeogenesis
all rxns in cytosol except PEP and pyruvate carboxylase
where do pep and pyruvate carboxylase occur
in the mito matrix
can malate DH be considered part of gluconeogen
yes
reciprocal regulation
must turn one on and the other off
how do the main control points fructose 6 ohosphate and fructose 1,6 bisphosphate work
through reciprocal regulation
what enzymes take place @ the same time
phosphofructokinase and fructose 1,6 bisphosphatase
why are substrate cycles importanttation
consume small amounts of atp and give a borader range of control
what needs to be regenerated to sustain glycolysis
NAD+
homolactic ferm
respiration that occurs in bacteria and animal cells w/ the absence of O2 to regenerate NAD+
what does LDH catalyze
prochiral differentiation
muscle lactate
transferred to the liver where it turned back to glucose via gluconeo
cori cycle
-muscle lactate taken bloodstream
- ldh converts lactate to glucose to glucose can be taken via the bloodstream
