What is repression in biology?
repression, in metabolism, a control mechanism in which a protein molecule, called a repressor, prevents the synthesis of an enzyme by binding to—and thereby impeding the action of—the deoxyribonucleic acid that controls the process by which the enzyme is synthesized.
How is gene expression is regulated by induction and repression?
Repression is a decrease in gene expression. Induction is an increase in gene expression due to the presence of an inducer. While our genes provide all the instructions for the proteins we make, our individual traits are influenced by the regulation of gene expression.
What is transcription repression?
Transcriptional repression is an essential mechanism in the precise control of gene expression. While these initial studies focused on regulation of the lactose operon of Escherichia coli, it was soon realized that transcriptional repression is a general mechanism affecting gene expression in prokaryotes.
What controls enzyme repression?
Enzyme repression is when the repressor molecules prevent the manufacture of an enzyme. Repression typically operates by feedback inhibition. For example, if the end product of a series of enzyme-catalyzed reactions is a particular amino acid, that amino acid acts as the repressor molecule to further production.
What is control gene?
Control genes, commonly defined as genes that are ubiquitously expressed at stable levels in different biological contexts, have been used to standardize quantitative expression studies for more than 25 yr.
Why is control of gene expression important?
Genes encode proteins and proteins dictate cell function. Therefore, the thousands of genes expressed in a particular cell determine what that cell can do. Thus, control of these processes plays a critical role in determining what proteins are present in a cell and in what amounts.
What is the induction and repression?
Enzyme Induction-Repression Enzyme induction refers to the increase in the amount of enzyme protein as a result of some stimulus, whereas enzyme repression refers to a decrease in enzyme after a stimulus. While common in bacterial enzyme regulation, they are observed less often in animal metabolism.
Can transcription factors be repressive?
Transcription factors, some of which bind to specific DNA sequences, generally either activate or repress promoter activity and thereby control transcription initiation. In addition, the repression of transcription is often intimately associated with chromatin re-organisation.
What is induction and repression?