What is conditional gene expression?
Gene expression is usually the transcription and translation of genes to form proteins. Protein synthesis is one of the most energy-expensive activities of the cell. For this reason, genes are regulated so that they aren’t expressed unless they are needed. Some genes are required for life and are always expressed (constitutive expression) but others require specific conditions where the protein product would serve a purpose (conditional). An example of this conditional expression is the lac operon in E.coli. The operon codes for enzymes needed to metabolise lactose to glucose and galactose. The genes are only expressed in conditions where lactose is present and glucose is not.
