How does phosphofructokinase PFK regulation in the liver dif

How does phosphofructokinase (PFK) regulation in the liver differ from PFK regulation in the muscle?

a) all of these answers are correct

b) Liver PFK inhibition by ATP is enhanced by citrate

c) Liver PFK is not affected by pH

d) Liver PFK responds to changes in blood glucose through the side product fructose 2,6-bisphosphate

Solution

C. Liver PFK is not affected by pH.

PFK is also inhibited by low pH levels which augment the inhibitory effect of ATP. The pH falls when muscle is functioning anaerobically and producing excessive quantities of lactic acid . This inhibitory effect serves to protect the muscle from damage that would result from the accumulation of too much acid.