Chapter 11.1: The Regulation of Gene Expression Occurs at Multiple Levels

Flashcards from Chapter 11.1 of Principles of Life, 3rd Edition.

Regulatory networks

Collections of interacting regulators that determine the expression level of a gene

• Allows for multi-faceted gene expression

Transcription regulation

The most common type of regulation due to the need for energy conservation

Inducers

Compounds that stimulate the transcription of specific inducible genes

• Includes genes required in particular conditions, such as those for triglyceride synthesis given high glucose levels

• Generally control catabolic pathways

Repressors

Compounds that reduce the transcription of specific repressible genes

• Includes genes that are normally expressed with reduced functionality when the product is present, such as synthesizers of nonessential amino acids

• Generally control anabolic pathways

Constitutive genes

Genes that are expressed most of the time at a constant rate in all cells

• Includes genes required for protein synthesis, such as tRNAs and ribosomal proteins

Transcription factors

Regulatory proteins that control whether a gene is active; includes repressors and activators

• Type of activation does not imply repressibility or inducibility, as both kinds may apply

Negative regulation

A type of regulation where a transcription factor binds to a specific site to reduce or prevent transcription

• Transcription factor serves as a repressor

Positive regulation

A type of regulation where a transcription factor binds to a specific site to increase transcription

• Transcription factor serves as an activator

DNA binding domain

The region in a protein that is able to bind to a particular sequence of DNA

• Enables recognition of specific sequences by transcription factors