Epigenetic Mechanisms and Chromatin Structure

These flashcards cover key concepts from the lecture notes on chromatin structure and epigenetic mechanisms.

Linker DNA is bound by __.

histone H1

Euchromatin is __ accessible than heterochromatin.

more

In eukaryotes, de novo DNA methylation is performed by __.

DNA methyltransferases (DNMTs)

The __ domain binds to methylated lysine.

Chromodomain

The key modification associated with transcriptional repression in heterochromatin is __ methylation.

H3K9

Insulators are DNA elements that prevent __ communication between two sequences when physically located between them.

cis

Histones can undergo post-translational modifications such as __, __, and __.

acetylation, methylation, phosphorylation

The primary function of trithorax group proteins is to __ genes and maintain them on.

activate

Bromodomain binds __, activating transcription.

acetylated lysines (Ac-K)

A common feature of imprinting is a __.

differentially DNA-methylated region (DMR)

The process by which a gene is turned off is called __.

gene silencing

The major type of RNA involved in translating the genetic code into proteins is __.

messenger RNA (mRNA)

The structure that forms when DNA is wrapped around histone proteins is called __.

nucleosome

The type of DNA that is tightly packed and generally not expressed is known as __.

heterochromatin

The DNA sequence that signals where transcription begins is called the __.

promoter

The removal of a methyl group from DNA is referred to as __.

demethylation

Highly repetitive DNA sequences, often found in centromeres, are called __.

satellite DNA

The enzyme responsible for adding RNA primers during DNA replication is __.

primase

The primary role of ribosomes is to __.

synthesize proteins

The modification of histones that typically leads to gene activation is known as __.

acetylation

The __ model of DNA replication proposes that each new DNA molecule consists of one old and one new strand.

semiconservative

Transcription factors are proteins that help regulate the transcription of __ genes.

specific

The free ends of linear chromosomes are protected by structures called __.

telomeres

The two main strands of DNA are held together by __ bonds between the nitrogen bases.

hydrogen

The region of DNA that is wound tightly and is not accessible for transcription is known as the __.

closed chromatin configuration

Responsible for RNA splicing in eukaryotes, the __ complex removes introns from pre-mRNA.

spliceosome

Long non-coding RNAs (lncRNAs) play roles in regulating gene expression by interacting with __.

chromatin

The overall structure of chromatin consists of DNA and __ proteins.

histone

DNA polymerases require a __ to initiate DNA synthesis.

primer

The __ phase of the cell cycle is when DNA replication occurs.

S phase

The sequence of DNA that codes for a trait is known as a __.

gene

What are the three components of a nucleotide? __, __, and __.

sugar, phosphate, base

Transcription occurs in the __ of eukaryotic cells.

nucleus

The process of converting RNA into protein is called __.

translation

The region that transcribes an RNA molecule from a DNA template is called a __.

transcription unit

Post-translational modifications can affect a protein's __ and __.

function, location

The process used by cells to repair damaged DNA is called __.

DNA repair mechanisms

During DNA replication, the __ strand is synthesized continuously, while the other strand is synthesized in fragments.

leading

DNA methylation typically occurs at the __ position of cytosine bases.

5th

The first amino acid in a newly synthesized protein is usually __.

methionine

RNA interference (RNAi) is a biological process where RNA molecules inhibit gene expression by __.

targeting mRNA for degradation

Transcription terminates when RNA polymerase encounters a __ signal.

termination

The structural modification of histones that usually leads to gene silencing is known as __.

methylation

The process of turning a gene on is referred to as __ of the gene.

activation

The region of DNA that binds transcription factors to initiate transcription is known as the __.

core promoter

The molecular machine that synthesizes RNA from a DNA template is called __.

RNA polymerase

The __ consists of multiple nucleotides joined together by phosphodiester bonds.

polynucleotide chain

The tertiary structure of a protein is determined by __ interactions.

non-covalent

The __ histones are specifically modified to facilitate the regulation of genes during the cell cycle.

variant

Amine modification at the amino acid level can influence a protein's __ and __.

interactions, stability

The mechanism of gene expression regulation involving small RNAs is termed __.

post-transcriptional regulation

The information stored in DNA is used to create __ that perform cellular functions.

proteins

Histone __ is a process that adds an acetyl group to lysine residues on histones to promote gene

Acetylation