Chapter18-Gene Regulation

These flashcards cover key concepts related to gene regulation and expression, focusing on mechanisms in both prokaryotes and eukaryotes.

Gene Regulation

The control of when and how much of a gene is expressed.

Operon

A DNA sequence that includes the structural genes and the elements that control their expression.

Repressible Operon

Transcription is usually on but can be inhibited when a small molecule binds to a regulatory protein.

Inducible Operon

Transcription is usually off but can be turned on when a small molecule interacts with the regulatory protein.

Feedback Inhibition

A cellular mechanism in which the end product of a metabolic pathway inhibits an enzyme involved in its synthesis.

Transcription Terminator

A specific DNA sequence that dictates termination of transcription.

Chromatin Modification

Changes to the structure of chromatin that can regulate gene expression by making DNA more or less accessible.

Differential Gene Expression

The process by which cells with the same genome express different sets of genes, leading to diverse cell types.

Epigenetic Inheritance

Heritable changes in gene expression that do not involve changes to the underlying DNA sequence.

RNA Processing

Modifications to RNA after transcription, including splicing, capping, and polyadenylation that prepare it for translation.

MicroRNA

Small non-coding RNA molecules that regulate gene expression by binding to complementary sequences in mRNA.

Histone Code Hypothesis

The idea that specific patterns of histone modifications can affect gene expression and chromatin structure.

Promoter

A specific DNA sequence where RNA polymerase attaches (at the start of transcription).

Structural Gene

Any gene that codes for a polypeptide.

Repressor

A regulatory protein that binds to DNA, blocking RNA polymerase.

Corepressor

A small molecule that cooperates with the repressor to turn the operon off.

Operator

A sequence of DNA that serves as the binding site for a repressor.

Transcription Terminator

Specific DNA sequence that dictates termination of transcription

Beta-galactosidase

breaks lactose down to simple sugar

Permease

a protein that facilitates the transport of lactose into the cell.

transacetylase

function unkown