Gene regulation in prokaryotes
- Study guide:
- Wikipedia article: Operon
- Wikipedia article: The Lac Operon
- Wikipedia article: The Arabinose Operon
- Wikipedia article: The Tryptophan Operon
Constitutive vs Adaptive Enzymes
Genes for constitutive enzymes are always on and the gene is always produced. Adaptive genes may be either inducible (generally off; may be turned on) or repressible (generally on; may be turned off).
Inducible Genes are generally enzymes necessary for catabolism and are only turned on if substrate is present as the substrate acts an inducer (effector).
Repressible Genes are generally enzymes involved in anabolism and are inhibited by feedback (the end product acts as a repressor for the gene)
- e.g. Trp operon