Chromatin and Epigenetics Lecture

This set of flashcards covers key vocabulary related to chromatin structure, epigenetics, and the mechanisms of gene regulation.

Nucleosome

The basic unit of eukaryotic chromosome structure, consisting of DNA wrapped around a core of histone proteins.

Histone Modifications

Covalent modifications to histone proteins, such as methylation and acetylation, that impact gene expression and chromatin structure.

Euchromatin

A less condensed form of chromatin that is generally associated with active gene expression.

Heterochromatin

A highly condensed form of chromatin that is typically transcriptionally inactive.

Methylation

The addition of a methyl group to DNA, usually affecting gene expression by inhibiting transcription.

Histone Acetylation

The addition of acetyl groups to histones, associated with transcriptional activation.

Linker DNA

The DNA sequences that connect nucleosome core particles and are exposed between them.

Solenoid Structure

A 3D coiled structure of condensed chromatin formed by wrapping nucleosomes around each other.

Chromatin-remodeling Complex

Enzymatic complexes that reposition DNA wrapped around nucleosomes to control gene accessibility.

Histone Code

The hypothesis that combinations of histone modifications can determine chromatin structure and gene expression.

5-methylcytosine

A modified form of cytosine in DNA resulting from methylation, often influencing gene expression.

ATP Hydrolysis

The chemical reaction that releases energy from ATP, utilized by chromatin-remodeling complexes to reposition nucleosomes.

Maintenance Methyltransferase

An enzyme that ensures DNA methylation patterns are inherited following DNA replication.

Coactivator Complexes

Complexes that assist in the transcriptional activation of genes by modifying the chromatin structure.

Corepressor Complexes

Complexes that inhibit gene transcription, often by promoting histone deacetylation.