glycolysis ivanov Flashcards
shuttles
Glycerol-3-P
Malate
Glycerol-3-P
1 NADH will produce ? ATP
1.5
Malate
1 NADH will produce ? ATP
2.5
G-3-P
produces how many ATP total?
30
Malate produces how many ATP total?
32
enzymes of the investment phase
hexokinase phosphoglucose isomerase phosphofructosekinase aldolase triose phosphate isomerase
molecules produced during investment phase
d-glucose—start
- glucose 6-phosphate
- fructose 6-phosphate
- fructose 1,6-biphosphate
- glyceraldehyde 3-phosphate
dihydroxyacetone phosphate
what happens to the fructose 1,3-biphosphate?
it goes through an aldol cleavage producing glyceraldehyde 3-phosphate
dihydroxyacetone phosphate
what enzymes accompany the ATP investments?
hexokinase
phoshofructokinase
what cells have no mitochondria?
RBC
What does aerobic glycolysis depend on?
Pa O2
number of mitochondria
NADH is
and electron carrier
What are the net products of glycolysis?
2 pyruvate
2 NADH
2 ATP
Anaerobic glycolysis is dependent on what enzyme?
lactate dehydrogenase
Anaerobic glycolysis produces what molecule?
Lactate
What are the enzymes of the generation phase?
- Glyceraldehyde 3-phosphate dehydrogenase
- phoshoglycerate kinase
- phoshoglycero-mutase
- enolase
- pyruvate kinase
glycolysis occurs where
cytosol
What is the pace setting enzyme for glycolysis?
phosphofructokinase
what inhibits phosphofructokinase
ATP
citrate
what is the substrate used by phosphofructokinase?
fructose 6-phosphate
vigorously contracting muscles show an increase in what reaction
conversion of pyruvate to lactate
If a pt showed very low lactate conversion after working out, what enzyme would be deficient
pyruvate kinase
which reactions in glycolysis are irreversable?
the rate limiting reactions
what is the oxif=dized product of NADH?
NAD+
will a fasting state speed up or slow down glycolysis, why?
a fasting state will slow down glycolysis due to the inhibition of phosphofructokinase. The enzyme is a rate determining enzyme and decreased levels of fructose 2, 6-biphosphate cause inhibition.
Fructose 2,6 phosphate is activated by
insulin
what are the products of the generation phase of glycolysis?
4 ATP
2 NADH
2 pyruvate
what enzyme is reponsible for the phosphorylation of glucose
hexokinase
what inhibits hexokinase
glucose 6-phosphate
hexokinase has a high affinity for
glucose
where is glucokinase found
liver parenchymal cells
islet cells of the pancreas
how does glucokinase differ from hexokinase
1.glucokinase only functions when the intracellular concentration of glucose in the hepatocyte is elevated
(helpful when eating a carb rich meal)
2. indirectly inhibited by fructose 6-phosphate
- its activity is increased due to the activity of insulin
What is the reaction following the phosphorylation of glucose?
glucose 6-phosphate is isomerized to fructose 6-phosphate
what is the catalyst of this reaction
phosphoglucose isomerase
What reaction happens to fructose 6-phosphate?
irreversable phosphorylation of fructose 6-phosphate to fructose 1,6-biphosphate
what regulates this reaction?
- activated by increased concentration of fructose 2,6-biphosphate (most potent activator)
- inhibited by increased ATP, Citrate
- activated by high AMP
What is the catalyst of this reaction?
phosphofructokinase-1 (PFK-1)
ATP is required investment during what reactions?
- glucose to glucose 6-phosphate
2. fructose 6-phosphate to fructose 1,6-biphosphate
What happens during the cleavage of fructose 1,6-biphospahte?
aldolase cleaves fructose 1,6-biphosphate to dihydroxyacetone phosphate and glyceraldehyde 3-phospahte
is this reaction reversable?
yes
What does triose phosphate isomerase do?
interconverts dihydroxyacetone phoshate and glyceraldehyde 3 -phosphate
what happens to dihydroxyacetone phosphate?
it is isomerized to glyceraldehyde 3-phosphate for further metabolism in the glycolytic pathway
what happens to the 2 molecules of glycrealdehyde 3-phosphate
they are oxidized to 1,3-biphosphoglycerate
what is the catalyst for this reaction
glyceraldehyde 3-phosphate dehydrogenase
What also happens during this reaction in glycolysis?
NAD+ is rduced to produce NADH + H+
What happens to 1,3 BPG?
it is conveted to 3-phosphoglycerate
(the high energy phosphate group is used to synthesize ATP from ADP
What is this reaction catalyzed by?
phosphoglycerate kinase
3-phosphoglycerate is then
shifted the phosphate group from carbon 3 to carbon 2 by the catalyst phosphoglycerate mutase
what happens to 2-phosphoglycerate
it is dehydrated by enolase
this results in the formation of a high energy enol phosphate contained in the PEP molecule
What happens to the PEP molecule?
PEP is converted to pyruvate by the enzyme pyruvate kinase
last irreversable reaction of glycolysis
produces ATP
What activates pyruvate kinase
elevated levels of fructose 1,6-biphosphate
T or F
The rate limiting reactions of glycolysis are irreversable.
T
Which reaction is the regulated reaction of the glycolytic pathway?
Fructose 6 phosphosphate—–>fructose 1,6 biphosphate
PFK-1
What would cause an increase in conversion of pyruvate to lactate?
vigourously contracting muscles
Red blood cells isolated from a patient showed abnormally low level of lactate production, which enzyme of glycolysis is deficient?
pyruvate kinase
