Eukaryotic Chromatin Modifications quiz Flashcards

Histone acetylation is the process of adding an acetyl group to histone proteins, which loosens chromatin structure and promotes euchromatin formation.

Histone acetylation loosens the chromatin structure, making DNA more accessible to RNA polymerase and promoting transcription.

Histone tails can be chemically modified by cellular enzymes, such as through acetylation, to regulate chromatin structure and gene expression.

Deacetylation removes acetyl groups from histones, resulting in tighter chromatin packing and a heterochromatin state, which reduces transcription.

DNA methylation is the addition of a methyl group to cytosine nucleotides, which typically blocks transcription by preventing RNA polymerase from accessing the promoter.

DNA methylation turns off gene expression by blocking RNA polymerase from binding to the DNA, thus preventing transcription.

Histone acetylation promotes transcription by loosening chromatin, while DNA methylation inhibits transcription by blocking RNA polymerase access.

Transcription factors are proteins that bind to specific DNA sequences to regulate transcription initiation.

General transcription factors bind to the promoter region and are required for the transcription of all genes.

Specific transcription factors bind to regulatory regions other than the promoter and are required for the transcription of specific genes.

Euchromatin is a loosely packed chromatin state that allows for active transcription.

Heterochromatin is a tightly packed chromatin state that generally represses transcription.

RNA polymerase binds to DNA and synthesizes RNA during transcription.

Acetylation increases gene expression by promoting a euchromatin state, making DNA more accessible for transcription.

Methylation decreases gene expression by blocking RNA polymerase from accessing the DNA, thus preventing transcription.

Eukaryotic chromatin is composed of DNA and histone proteins. DNA is wrapped around histone proteins to form nucleosomes, which are the basic units of chromatin.