Constitutively expressed

Definition

Constitutively expressed genes are continuously active and produce their gene products at a constant rate, regardless of environmental conditions. These genes are essential for basic cellular functions.

5 Must Know Facts For Your Next Test

1. Constitutively expressed genes are often involved in fundamental cellular processes like metabolism and maintenance.
2. They are not subject to regulation by inducers or repressors as operons are.
3. Housekeeping genes, such as those encoding for ribosomal RNA and enzymes of the central metabolic pathways, are typically constitutively expressed.
4. Mutations affecting constitutively expressed genes can be particularly detrimental because they disrupt essential cellular functions.
5. In contrast to inducible or repressible operons, the expression level of these genes does not fluctuate in response to external stimuli.

Review Questions

Related terms

Inducible Operon: A set of genes whose expression increases in response to an inducer molecule.

Repressible Operon: A set of genes that can be turned off by a repressor molecule when a specific substance is present.

Housekeeping Genes:

Genes that are typically constitutively expressed and necessary for the maintenance of basic cellular function.