Control of Gene Expression in Eukaryotes

These flashcards cover key concepts in the control of gene expression in eukaryotes, including transcription, modification processes, and the roles of various proteins and enzymes.

What are the main processes of the central dogma of molecular biology?

Replication, transcription, and translation.

What is the name of the enzyme that copies DNA during replication?

DNA polymerase.

What enzyme is responsible for converting DNA into RNA?

RNA polymerase.

What is the difference between exons and introns?

Exons are expressed sequences, while introns are intervening sequences that are spliced out.

What modifications occur during post-transcriptional modification?

Splicing out introns, adding a cap at the 5' end, and adding a poly-A tail at the 3' end.

What type of chromatin is relaxed and accessible for transcription?

Euchromatin.

What type of chromatin is condensed and inaccessible?

Heterochromatin.

What are transcription factors?

Proteins that stimulate transcription by assembling transcription machinery.

How do enhancers differ from promoters?

Enhancers are further away from the gene and regulate transcription, whereas promoters are located close to the gene start site.

What does acetylation of histones do to DNA?

It makes the DNA active and transcriptionally accessible.

What effect does methylation of DNA have?

It makes the DNA inactive, leading to heterochromatin formation.

What role do hormones like cortisol play in gene expression?

They can activate or repress gene expression by binding to specific response elements on DNA.

What is the function of the TATA box in transcription?

It acts as a promoter region that initiates transcription.

What happens to mRNA before it exits the nucleus?

It undergoes post-transcriptional modifications such as capping, tailing, and splicing.

What is histone deacetylation associated with?

It is associated with inactive DNA and results in the formation of heterochromatin.

What is the function of RNA polymerase II?

It synthesizes messenger RNA (mRNA).

What is the significance of the AUG codon in mRNA?

It is the start codon that codes for the amino acid methionine.

What is a nucleosome?

A structural unit of DNA wrapped around histone proteins.

What is the significance of RNA polymerase I?

It synthesizes ribosomal RNA (rRNA) and is essential for ribosome assembly.

What is the significance of RNA polymerase III?

It synthesizes tRNA and some small nuclear RNA (snRNA), playing a crucial role in protein synthesis and gene regulation.