Introductory Microbiology

Gene regulation and expression

• The genes are always pressed in the bacterial chromosomes but their expression is always controlled. Here, the gene expression refers the mRNA and protein synthesis. The expression of the gene was systematically controlled some proteins. Whenever needed, the genes will be expressed to get the protein (i.e. enzymes). Regulating protein synthesis at the gene level is energy efficient because proteins are synthesized only as they are needed. Constitutive enzymes are always present in a cell. Examples are genes for most of the enzymes in glycolysis. For these genetic regulatory mechanisms, the control is aimed at mRNA synthesis.