Which of the following method is for regulating the enzyme's quantity :

Enzyme's quantity i.e. amount of enzyme synthesized can be controlled at the level of gene expression, by inducing or repressing the gene or enzyme breakdown by enzyme degradation. Other methods such as Phosphorylation, Acetylation are covalent methods of regulation of enzyme activity. They do not affect the quantity of enzyme. Most common method of enzyme activity regulation is Phosphorylation, for e.g. catabolic enzymes are active in Phosphorylated state. Enzymes are not regulated by glycosylation