Glycolysis Flashcards
fermentation of pyruvates to what?
lactic acid by bacteria
oxidation of reduced fuel (glucose) to generate E to form of ATP and NAD(P)H
metabolism
electrons are fallin gdown an electrial potential gradient from ____ to ______
reduced (glucose) to oxidized (oxygen)
metabolism doesn’t happen in
vacuum
what are involved to move metabolites in and out of cell?
many transporters
they talk to each other - complexity
GLU1 has Km value
~1mM
housekeeping one
GLU2 has Km?
high Km for glucose (10-20mM)
where is GLU2 present?
in the liver means that liver will take up glucose only when the blood glucose conc. is raised (after meal)
in fast state, GLUT2 does waht?
allows for the export of glucose from the liver
GLUT3 has Km?
low Km. ( present in brain)
GLUT4 transporters are sequestered in membranes of intracellular vesicles untill?
increase in blood insulin (from pancreas) concen. leads to recuitment of GLUT4 to the plasma membrane
insuline signal molecule here.
GLUT5 is
fructose transporter
glycolysis is what kind of process?
anaerobic process
doesn’t require O2
glucose into pyruvate, then to what in anaerobic condition?
lactate
recycling NADH -> NAD+
glucose into pyruvate, then to what in aerobic?
to acetyl coa => TCA => electron transport chain –> oxygen is final elec acceptor
*much more efficient (x15) than anaerobic
Glycolysis - synthesis of ATP is by?
substrate-level phosphorylation
synthesis of ATP in mitochondria is by?
oxidative phosphorylation
committed step of glycolysis is catalyzed by?
phosphofructokinase 1
hexokinase is regulated step but not first commited step becasue?
its product glucose 6-p is link to many other pathway
by adding the strongly-charged po4, glucose is now?
now trapped inside the cell
dehydrogenase
taking away (H-e- attached) electron and gives it to something else
net reaction of glycolysis
glucose + 2ADP + 2NAD+ +2Pi ->
2pyruvate + 2 ATP + 2NADH + 2H+ + 2H2O
phosphoenopyruvate + ADP + H+ –> Pyruvate + ATP
what enzyme/
pyruvate kinase
hexokinase reaction; in vivo, nucleotide phosphates are typiclly associated with ____ ti stablize the charge
Mg++
most NTP-utilizing enzymes require __ as a cofactor
Mg++
multiple forms of hexokinase occur in mammalian tissues and yeast?
Isozymes
PFK-1 is metabolically _____ and critical regulatory point for glycolysis in most cell
irreversible
PFK-1 is the first committed step of glycolysis
enzyme in microbes that decarboxylates pyruvate to make acetaldehyde (which will become ethanol)
pyruvate decarboxylase
enzyme that decarboxylates pyruvates to form acetyl coa for TCA cycle
pyruvate dehydrogenase
this enzyme adds CO2 to pyruvate to make oxaloacetate for anapleurotic reactions and for gluconeogensis
pyruvate carboxylase
ATP is ___ and ____ for PFK1
substrate and allosteric inhibitor
this is formed from F6P by the enzyme phosphofructokinase -2( PFK-2)
F2,6BP
fructose 2,6 - bisphosphate
GAPDH
another site for arsenic poisoing
three major fates of pyruvate
anerobic : to 2ethanol (in bacterial) to 2 lactate (muscle)
aerobic : to 2 acetyl coa
Oxidative decarboxylation catalyzed by?
pyruvate dehydrogenase complex - know the mechanism!
2 carbon acetyl groups passed from ___ to _____
phosphate group to thiol group
lipoic acid cofactor ‘active site’ cycles between what?
osidized -s-s and reduced -SH HS-
Anaerobic fate of pyruvate?
Anaerobically, there is no TCA cycle to burn up the reduced NADH.
MUST RECYCLE NADH NAD+ otherwise glycolysis will stop
Electrons are a waste product
Reduction of Pyruvate to Lactate (Eukarotic muscles - anaerobic)
This reaction regenerates NAD+ for use by GAPDH in glycolysis
what effect is slowing down glycolysis in presence of oxygen?
pasteur effect
net ATP in glycolysis
2 ATP
4 in, 2 out
