Cells carry out anabolic as well as catabolic pathways, with some enzymes functioning in both types of pathways. (a) explain why these enzymes catalyze near-equilibrium reactions. (b) explain why opposing anabolic and catabolic pathways must have diff erent enzymes for at least one of the steps.

a) Substrate compulsory to hexokinase causes large conformational variations which forms the binding site for ATP

and eliminates water from active site. This averts ATP from binding in the absenteeism of the other substrate,

which would endorse hydrolysis in its place of phosphate transfer.

b) Opposing anabolic and catabolic pathways have diverse enzymes that catalyze opposite irreparable

reactions. These are differentially regulated when one is stimulated the other is reserved to guarantee that

only one pathway is efficient at a time.