Cooperativity & Glycolysis: Regulation of Enzymes

[DemiMike]

is it true that cooperativity is rare in enzymes with tertiary structure
and that Glycolysis is inefficient and therefore rarely found in present day organisms

i am not sure.. but iwas also wondering that a particular enzyme is likely subject to only a few forms of the regulation we discussed in lecture

=o

 

[alxm]

If glycolysis is inefficient and rare, what am I doing storing up all this glycogen in my muscles and liver?

 

[DanP]

is it true that cooperativity is rare in enzymes with tertiary structure
and that Glycolysis is inefficient and therefore rarely found in present day organisms

i am not sure.. but iwas also wondering that a particular enzyme is likely subject to only a few forms of the regulation we discussed in lecture

=o

Glycolysis is a major energetic pathway in any organism I can think of. The net yield of ATP in glycolisis is quite small , of only 2 ATPs.This pushes many ppl to label glycolisis as an "inefficient pathway"

But there are other considerations as well. Skeletal muscles are highly efficient in breaking down glucose at very high rates. In effect, this yields large quantities of ATP formation in quite short times. It is this high rate which makes possible high intensity efforts, which in no way can be sustained by oxidative metabolism.

Besides, oxidative metabolism and glycolityc metabolism are intrinsically linked. The lactate which is formed as a result of fast glycolityc pathways is moved, through the intracellular lactate shuttle, from cytosol to mitochondria, where it is further oxidized. Cell to Cell lactate shuttles also appear to exist. This is opposed to the "classic" view where the only fate for the lactate produced as the result of fast glycolisis is reconversion to glucose through the pathways of Cori cycle.

As for regulation what did you discussed in lecture ?