ABSTRACT
A s note d earlier , th e velocit y o f an y enzyme-catalyze d reactio n i s dependen t
upon th e amoun t o f effectiv e enzym e present . E n z y m e biosynthesis, lik e tha t o f
all proteins , i s unde r geneti c control , a long-ter m process . Biosynthesi s o f en -
zymes ma y b e increase d o r decrease d a t th e genom e level . Variou s hormone s
can activat e o r repres s th e mechanism s controllin g gen e expression . E n z y m e
levels ar e th e resul t o f th e balanc e betwee n synthesi s an d degradation . T h i s
enzyme turnove r ma y b e altere d b y divers e physiologica l conditions , b y hor -
mone effects , an d b y th e leve l o f metabolites .
