Transcription Quiz

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Questions and Answers

Which region of a gene contains the consensus sequence?

Terminator region

Template strand

Coding region

Promotor region (correct)

Which region of a gene specifies the end of transcription?

Terminator region (correct)

Promotor region

Template strand

Coding region

Which strand of DNA is transcribed into RNA?

Non-template strand

Template strand (correct)

Sense strand

What is the main key enzyme for transcription?

RNA polymerase Signup and view all the answers

In which direction does RNA polymerase work?

5' to 3' Signup and view all the answers

What is the first stage of transcription?

Initiation Signup and view all the answers

What is the consensus sequence recognized by transcription initiation factors in eukaryotes called?

TATA box Signup and view all the answers

What is the role of general transcription factor TFII?

Recognize and bind the TATA box Signup and view all the answers

Where is the TATA box located in relation to the transcription start site?

~25 nucleotides upstream Signup and view all the answers

What is the role of silencers in transcription initiation?

They inhibit gene transcription Signup and view all the answers

What happens during the elongation phase of transcription?

RNA Polymerase II moves downstream along the DNA Signup and view all the answers

What is the role of chromatin remodeling complexes during elongation?

They help RNA Polymerase II navigate the chromatin structure Signup and view all the answers

What is the role of histone chaperones during elongation?

They disassemble/reassemble nucleosomes Signup and view all the answers

What is the role of DNA topoisomerase during elongation?

They remove supercoils Signup and view all the answers

What are the three main ways in which pre-mRNA is processed in eukaryotes?

Splicing, capping the 5' end, polyadenylation of the 3' end Signup and view all the answers

What is the function of the 5' cap on mRNA?

It facilitates export of the mRNA into the cytosol Signup and view all the answers

What is the function of the poly-A tail on mRNA?

It protects the mRNA from degradation Signup and view all the answers

Prokaryotic mRNA has a cap and a tail like eukaryotic mRNA but it doesn't get spliced

False Signup and view all the answers

Prokaryotic mRNA is considered polycistronic because..

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Prokaryotic mRNA does NOT get exported from the nucleus

True Signup and view all the answers

Steps of prokaryotic and eukaryotic transcription are the same except for the processing of mRNA

True Signup and view all the answers

Match the following elements of the transcription process to their respective functions:

TATA box = Binding site for the transcription factor TFIID Silencers = Binding site for repressor proteins that inhibit gene transcription Enhancers = Binding site for transcriptional activator proteins that increase the rate of transcription DNA topoisomerase = Enzyme that relieves super-helical tension during transcription elongation Signup and view all the answers

Match the following elements of pre-mRNA processing in eukaryotes to their respective functions:

Splicing = Removal of intron sequences from the transcribed RNA 5’ cap = Facilitates export of the mRNA into the nucleus and is involved in translation Polyadenylation of 3’ end = Protects the mRNA from degradation and facilitates export from the nucleus Histone chaperones = Assist in partially disassembling & reassembling nucleosomes as an RNA Polymerase passes through Signup and view all the answers

Match the following elements of prokaryotic and eukaryotic transcription to their respective characteristics:

Eukaryotic transcription = Involves 5’ cap, splicing, and poly-A tail Prokaryotic transcription = Does not require 5’ cap, splicing, or poly-A tail Eukaryotic mRNA = Requires export from the nucleus Prokaryotic mRNA = Does not require export from the nucleus and can begin translation right away Signup and view all the answers

Study Notes

Gene Structure and Transcription

Consensus sequence is found in the promoter region of a gene.
The termination sequence specifies the end of transcription.
The template strand of DNA is transcribed into RNA.
RNA polymerase is the main enzyme for transcription.
RNA polymerase synthesizes RNA in the 5' to 3' direction.

Stages of Transcription

First stage of transcription is initiation.
The consensus sequence recognized by transcription initiation factors in eukaryotes is called the TATA box.
General transcription factor TFII plays a role in recruiting RNA polymerase to the promoter.

TATA Box and Transcription Initiation

The TATA box is located about 25-30 base pairs upstream of the transcription start site.
Silencers are DNA elements that repress transcription initiation by binding repressor proteins.

Elongation Phase of Transcription

During elongation, RNA polymerase adds nucleotides to the growing RNA strand.
Chromatin remodeling complexes facilitate access to DNA by altering chromatin structure during elongation.
Histone chaperones assist in reorganizing nucleosomes as transcription progresses.
DNA topoisomerase alleviates supercoiling ahead of RNA polymerase during elongation.

Pre-mRNA Processing in Eukaryotes

Pre-mRNA is processed through splicing, capping, and polyadenylation.
The 5' cap on mRNA protects the mRNA from degradation and assists in ribosome binding.
The poly-A tail on mRNA enhances stability and aids in the export of mRNA from the nucleus.

Prokaryotic vs. Eukaryotic mRNA

Prokaryotic mRNA is polycistronic, meaning it can encode multiple proteins from a single RNA molecule.
Unlike eukaryotic mRNA, prokaryotic mRNA does not get processed into introns/exons and lacks a cap and a tail.
Transcription and translation occur simultaneously in prokaryotes since there is no nuclear membrane.

Comparison of Transcription Processes

Steps of transcription are similar in prokaryotes and eukaryotes, aside from the processing of mRNA.
Prokaryotic mRNA does not undergo splicing and remains in the cytoplasm, while eukaryotic mRNA is exported after processing.

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Description

Test your knowledge on transcriptional units and gene structure! This quiz will cover the three general regions found in all genes - the promoter region, coding region, and terminator region. Challenge yourself to identify key elements such as the transcription start site and template strand. Get ready to dive into the world of gene transcription!