nadiabarati
|
30. An increase in the activity of which of the following enzymes is most likely to increase the rate of metabolism of glucose 6-phosphate through glycolysis in the liver? A) Fructose 1,6-bisphosphatase B) Fructose 1,6-bisphosphate aldolase (aldolase A) C) Fructose 2,6-bisphosphatase D) Glucokinase E) 6-Phosphofructo-1-kinase
PLEASE explain your answer
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
it is PFK-1 that is rate limiting. but PFK-2 is the allosteric regulator of PFK 1. so answer is PFK-2. but as PFK-2 is not given here and as PFK-2and F-2,6BPase is a bifuntional enzyme. i will say that answer is F-2,6-BP ase (actually working reverse as PFK-2)answer is C
___________________
If you think you can You can! If you think you cant you are right again!!
|
| nadiabarati
|
oh my God, I never heard of 1 and 2. I just know phosphofructokinase. I studied Lehninger for Bio
what is your source for bio?
|
| robin082006
Forum Hero
Topics: 471
Posts: 5,125
|
1 and 2 in Kaplan Biochemistry note
___________________
The Key to Succeed is Patience.
|
| coolmavs
Forum Elite
Topics: 21
Posts: 327
|
Agreed that PFK 2 is the enzyme that is a regulator of PFK 1, and Fructose 2,6- Biphospahatase can be the answer, I am not sure that it is the answer since the question states which enzyme is likely to increase the rate of Glycolysis and for this to happen the F 2,6-BPase enzyme would need to be inhibited. Actually if I may say the answer choices appear ambiguous..However I would say the answer is PFK-1 simply because it s the rate limiting step.
Robbin could you pls elaborate on what you are trying to say?
Nadia, what is the question source?
___________________
Yeh Zeher bhi, yoon piya hai.....Jaise sharaab ho!!!!
|
| nadiabarati
|
robbin is naswering my Q regarding PFK1 andPFK2
Drvirgo had posted the question in this forum, I don't know the source
|
| coolmavs
Forum Elite
Topics: 21
Posts: 327
|
OK, got your point!
___________________
Yeh Zeher bhi, yoon piya hai.....Jaise sharaab ho!!!!
|
| drk1980
Forum Guru
Topics: 147
Posts: 1,038
|
agree wth COOLMAVS.
Increasing the rate of glyolysis is directly and ultimately done by the rate limiting enzyme--> PFK1(choice E) 6-Phosphofructo-1-kinase) .....wch, as already mentioned, is allosterically activated by the substrate Fructose 2,6 bisphosphate.
Fructose 2,6 bisphosphate is converted from fructose 6-phosphate by PFK2 enzyme[when this enzyme is active and working, FBP2(fructose2,6 bisphosphatase) shd be inactive(dephosphorylated form of this enzyme complex, during Insulin state)...and vice versa(phosphorylated form during glucagon state)]. plz correct me...
As for the other choices B and D...they arnt rate-limiting....and choice A is a gluconeogenesis enzyme.
|
| vamsi2004
Forum Elite
Topics: 7
Posts: 144
|
so the final answer is E - right..
|
| MRMAVERICK
Forum Guru
Topics: 40
Posts: 713
|
ya it seems that thsi is the best answer e
|
|
| |
| | | | | | | | | | |
