Reciprocal Control & substrate cycles Flashcards
What is reciprocal control
when two separate enzymes doing one conversion (A to B) and the other is doing another conversion (B to A), this means they both need to be controlled in reciprocal ways.
Controlled by the same thing effectors, but in different ways, to do different things.
substrate cycles
sitting and spinning with metabolites. Most likely between PFK1 and FBPase1. Can dam up your metabolite , and then let a bunch out, which allows us to decide if we want to use it all or let a little bit of it go.
There is an energetic price, but the benefit is: if you really need to turn on glycolysis fast, there is a lot of built up metabolite to turn it on fast.
Allows for quick fight or flight.
WHY IS THERE A PRICE?
laws of thermodynamics
Each substrate cycle has what?
reciprocal control and cycles enhance effect of allosteric regulators (means if both affected by same effector but in different ways, that enhances the regulation for both enzymes)
HK and G6Pase substrate cycle is key in liver why
livers job is to buffer blood glucose levels
which HK is present in the liver?
HK-IV (four)