BIOLOGY 1A03 Lecture 10: Transcription in Eukaryotes and Export of mRNA

16 views4 pages

champagnesea-lion879

7 Feb 2017

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

doinhumolalala and 39849 others unlocked

BIOLOGY 1A03 Full Course Notes

Verified Note

9 documents

Document Summary

Part 1: transcription and mrna processing in eukaryotes. Transcription in eukaryotes uses the same principles as in prokaryotes. As in prokaryotes, eukaryotes also have speci c promoter regions in the dna sequence which indicate transcription start points, but these promoters have a greater degree of complexity. Another level of complexity in eukaryotes is the presence of three different types of rna polymerase, named simply rna polymerase i, ii and iii. Rna polymerases i and iii transcribe structural, non-coding rnas. Rna polymerase i transcribes the genes for the ribosomal rnas (rrnas), and rna polymerase iii transcribes the genes for the transfer rnas (trnas), as well as other small regulatory rna molecules. It is rna polymerase ii that transcribes the messenger. Rnas, which serve as the templates for production of protein molecules. Similar to prokaryotes, there are core promoter consensus sequences required to set up a transcription initiation complex, speci c for the particular rna polymerase and gene being transcribed.

Related Questions

Eukaryotic transcription normally takes place on a chromatin template at nuclease-accessible sites.(True/False)

*After promoter clearance by RNA polymerase II:

A) all associated factors remain bound to the polymerase for elongation.

B) a subset of factors remain at the promoter region.

*Which of the following statements is FALSE?

A) RNA polymerase II is responsible for the transcription of genes encoding protein-coding sequences only.

B) Many promoters recognized by RNA polymerase II contain regulatory elements several kbp upstream of the initiation site.

C) TFIIB has a role in converting a closed-promoter into an open-promoter complex.

D) The C-terminal domain of the largest subunit of RNA pol II undergoes extensive phosphorylation prior to transcription elongation.

E) A multiprotein complex is involved in communication between upstream control elements and proteins bound at the promoter.

C) no further elongation factors are acquired by the polymerase.

D) no further chromatin remodeling is required.

E) transcription continues until the polymerase reaches the poly (A) tail

*In eukaryotes RNA polymerase I transcribes all of the ribosomal RNA components.(TRUE/FALSE)

Which type of RNA is unique to eukaryotes?

		mRNA
		rRNA
		tRNA
		snRNA
		Its a trick, all cells have all four types of RNA.

1 points

QUESTION 2

The region of DNA to which RNA polymerase binds to initiate transcription is the:

		origin
		promoter
		enhancer
		none of the above are correct

1 points

QUESTION 3

Holoenzyme:

		is RNA polymerase core enzyme.
		is sigma factor.
		is core plus sigma factor.
		none of the above are correct.

1 points

QUESTION 4

Which of these is formed FIRST when RNA polymerase binds to a promoter?

		The closed promoter complex
		The open promoter complex
		A rho-independent terminator
		none of the above are correct.

1 points

QUESTION 5

A hairpin loop followed by a run of Us:

		is the sequence formed in the sense strand of a gene using a rho-independent terminator.
		is the sequence recognized by the rho protein.
		is the structure formed in RNA that causes rho-independent termination.
		is formed immediately after the open promoter complex is formed.

1 points

QUESTION 6

RNA polymerase:

		reads the template strand of the DNA in the 3' to 5' direction.
		synthesizes the RNA in the 5' to 3' direction.
		can begin transcription without a primer.
		all of the above are correct.

1 points

QUESTION 7

Which of the following statements is FALSE?

		Bacteria like E. coli have only one type of sigma factor.
		RNA polymerase has no proofreading activity.
		The promoter of a gene is upstream of the RNA-coding region.
		Bacterial transcriptional terminators are copied into RNA to cause termination.

1 points

QUESTION 8

If the template strand of a gene has the sequence 5' ATGCGAT 3', then:

		the RNA produced will have the sequence 5' AUGCGAU 3'.
		the RNA produced will have the sequence 5' UAGCGUA 3'.
		the RNA produced will have the sequence 5' AUCGCAU 3'.
		None of the above are correct.

1 points

QUESTION 9

The sense strand:

		is the lagging strand
		is also the template strand.
		always goes left to right.
		none of the above are correct.

1 points

QUESTION 10

Which of these is transcribed but not translated?

		mRNA
		tRNA
		rRNA
		all of the above
		tRNA and rRNA are transcribed but not translated.

please help i am a bit confused

1. What is the term when the product of a biochemical pathway inhibits the activity of the first enzyme of a pathway?

		feedback inhibition.
		activator inhibition.
		diffusional regulation.
		enzyme activation.

2. Through control of gene expression, prokaryotes respond to changing __________ conditions.

		internal
		protein
		environmental
		genetic

3. A protein that negatively regulates transcription by binding to the operator is known as the

		operon
		repressor
		activator
		inducer

4. During attenutation, when tryptophan levels are high, the ________ stem-loop forms and transcription ________ the trpL gene.

		1-2, ends just past
		3-4, ends just past
		1-2, continues beyond
		3-4, continues beyond

5. The process of turning on the expression of a gene in response to a substance in the environment is called:

		constituation.
		repression.
		induction.
		catabolism.

6. What is a function of some specific transcription factors?

		to bind to the promoter region of the gene to facilitate the proper alignment of the RNA polymerase
		to bind to the centromere to induce meiosis
		to bind to enhancer regions to help regulate gene transcription
		to bind to the operator to recruit sigma factor

7. How does exposing an E.coli cell to glucose affect the regulation of the lac operon via CAP?

		cAMP binds to CAP and transcription is increased.
		cAMP binds to CAP and transcription is decreased.
		cAMP does not bind to CAP and transcription is increased.
		cAMP does not bind to CAP and transcription is decreased.

8. The lac repressor protein works when mutations in the repressor gene and structural genes are:

		in cis or in trans.
		in trans only.
		in cis only.
		in both prokaryotes and eukaryotes.

scarletwombat949

BIOLOGY 1A03 Lecture 10: Transcription in Eukaryotes and Export of mRNA

BIOLOGY 1A03 Full Course Notes

Document Summary

Get access

Related Questions