Glycolysis Flashcards
When the B cells of the pancrease cannot respond to high blood glucose levels, what has been mutated and inherited?
glucokinase
when does glucokinase become very active?
when there is a higher than normal concentration of glucose
if the mitochondria is absent in red blood cells, how do they get there energy supply?
from glycolysis
what is the most important regulated step?
PFK1
why are the regulated steps irreversible?
they are irreversible because energy is being added in the form of ATP
what is the first rate limiting step?
hexokinase and glucokinase
why does glucokinase need to be phophorylated?
it needs to be phosphorylated, so that it can stay in the liver
after glucose is phosphorylated what is the next step?
it is changed from a aldose to a ketose..by phosphoglucose isomerase
why is the second rate limiting step important?
because it is the committed step
what happens in the 3rd step of glycolysis?
phosphofructokinase adds another phosphate to fructose to create fructose 1,6 bisphosphate
what is PFK-1 inhibited by?
ATP, citrate, Fructose bisphosphotASE-2, glucagon
what activates PFK-1?
Fructose 2,6 bisphosphate, AMP, ADP,PFK-2, insulin
what makes fructose 2,6 bisphosphate?
PFK-2
when insulin come into the cell how does it activate PFK2?
it activates it by dephosphorylating it
what are the bidirectional enzymes?
pfk2(gets dephosphorylated) and fructose bisphosphotase 2 (phosphorylated)
when glucagon is present what happens to PFK2?
PFK2 in phosphorylated and becomes inactive to prevent glycolysis, while fructose 2 bisphosphotase becomes active for gluconeogenesis
what does aldose do to fructose 1, 6 bisphosphate?
it cleaved it into 2 trioses( dihydroxyacetone phosphate and glyceralaldehyde 3 phosphate
where is aldose A present?
in the muscle
where is aldose B present?
in the liver
what does glyceraldehyde 3 phosphate dehydrogenase result in in the energy producing phase?
NADH
since dihydroxyacetone phosphate cannot fed into glycolysis what does it have to form into by triosephosphateisomerase?
glyceraldehyde 3 phosphate
what does phosphoglycerate kinase result in the formation of?
1,3-bisphophosglycerate and ATP (substarte level phosphorylation)
when 1,3 bisphosphoglycerate is formed, why is it important?
it is important because it is a high energy intermediate that results in in the formation of ATP without involving the electron transport chain-
What type of reaction is involved with 1,3-BPG?
it is a substrate level phosphorylation reaction which is important during periods of low oxygen.. hypoxia- this make ATP in its own- it can add a phosphate group directly to ADP to form ATP- without involvment of electron transport chain
what does phosphoglycerate kinase form?
3-phosphoglycerate
what does phosphoglycerate mutase produce?
2- phosphoglycerate
what does arsenate inhibit?
stops the formation of 1,3 bisphosphate by inhibiting glyceraladehyde phosphate dehydrogenase
Arsenic disrupts ATP production through several mechanisms. At the level of the citric acid cycle, arsenic inhibits pyruvate dehydrogenase and by competing with phosphate it uncouples oxidative phosphorylation, thus inhibiting energy-linked reduction of NAD+, mitochondrial respiration, and ATP synthesis.
why is phosphoenolpyruvate a high energy compound?
Its a high yield energy compound that results in the formation of ATP, without the involvment of the ETC in mitochndria(substrate level phosphorylation)
why are substrate level phosphorylation reactions important during periods of low oxygen(hypoxia)?
because they can produce ther own ATP without the involvment of the ETC in mitochondria
