explanation needed

[drkooks]

glucokinase has higher Km than hexokinase which is imp for liver cell gluconeogenis ...
this is from decks ..can someone explain please ..

 

[doc76]

glucokinase has higher Km than hexokinase which is imp for liver cell gluconeogenis ...
this is from decks ..can someone explain please ..

hi
Glucokinase is an enzyme that facilitates phosphorylation of glucose to glucose-6-phosphate. Glucokinase occurs in cells in the liver, pancreas, gut, and brain of humans and most other vertebrates. In each of these organs it plays an important role in the regulation of carbohydrate metabolism by acting as a glucose sensor, triggering shifts in metabolism or cell function in response to rising or falling levels of glucose. Glucokinase can only phosphorylate glucose if the concentration of this substrate is high enough; its Km for glucose is 100 times higher than that of hexokinases I, II, and III.
i hope this helps

 

[drkooks]

thanks but my Q is ..is not glucokinase in liver promoting glycolysis and not gluconeogenesis ....and in decks it says it is imp for the hepatocytes criteri of being able to perform gluconeogenesis

 

[drkooks]

one more
in decks
cori cycle is major fate of pyruvate in
lense and cornea
testes
kidney medulla
WBC


i understand the cycle for RBC and muscle during exercise but why the others??

 

[foreigndentist]

In this statement it means that the glucokinase has higher Km & hexokinase has lower Km
Small value of Km means that the enzyme has higher affinity for substrate & vice-versa.
Hexokinase's low Km allows the increased efficiency of phosphorylation & metabolism of glucose even if tissue conc. of sugar is low. which helps liver( IN TISSUES IS CORRECT NOT LIVER) to metabolise glucose when body's amt of glucose decrease. Hope I made it clear. If you have any doubts feel free to shoot.

 

[drkooks]

glucokinase is the one used in liver not hexokinase

 

[doc76]

thanks but my Q is ..is not glucokinase in liver promoting glycolysis and not gluconeogenesis ....and in decks it says it is imp for the hepatocytes criteri of being able to perform gluconeogenesis[/q
Hepatocytes are the predominant cell in the liver parenchyma. The liver takes up glucose and stores it as glycogen after a carbohydrate meal when blood glucose is plentiful. During fasting conditions, the liver releases glucose from glycogen, generates glucose by gluconeogenesis, and exports it into the blood. The separate liver promoter allows glucokinase to be regulated differently in hepatocytes than in the neuroendocrine cells
i am not sure if this is right ans but i found this
hope this helps

 

[foreigndentist]

Yeah u r right....
In liver it is glucokinase which helps in glycolyis . But still above explanation is true for the hexokinase.

In glucokinase (High Km & High Vm)functions when glucose is elevated .
Gluckokinase allows liver to work as explained above by doc 76.(double checked in the book) & it decreases hyperglycemia.

 

[drkooks]

one more explanation please

also in decks
majority of energy conserved during catabolism occur during end of reaction of E transport chain ...
well is not it energy produced ....??


also in decks the use of fermentation and anaerobic glycolysis is the same

is not the fermentation the one done by yeast to produce alcohol???

please reply and clear my doubt
thanks

 

[doc76]

one more explanation please

also in decks
majority of energy conserved during catabolism occur during end of reaction of E transport chain ...
well is not it energy produced ....??


also in decks the use of fermentation and anaerobic glycolysis is the same

is not the fermentation the one done by yeast to produce alcohol???

please reply and clear my doubt
thanks

i think use of fermentation and anarobic glycolysis is same becoz both are used when energy is required in absence of oxygen.
hpoe this helps

 

[drkooks]

in decks the junctional epith in healthy gingiva is entirely on enamel above CEJ

and in another one ..which is more logic to me ..the apical extent of JE is CEJ

can someone confirm

 

[fefzie]

in decks the junctional epith in healthy gingiva is entirely on enamel above CEJ

This is correct. if it goes below CEJ or is at CEJ it is not healthy gingiva.