Biochemistry 2280A Lecture Notes - Lecture 18: Nuclear Pore, Snrnp, Branch Point

17 views2 pages

chocolatekangaroo367

14 Apr 2020

School

Department

Course

Professor

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

Document Summary

Topic 18/19 - eukaryotic transcription + mrna processing. Odd 7-methylguanasine at the end of the 5" end of the primary rna transcript. Often called a 5" cap: 5" cap ------------------------------- 3" Identifies the 5" end of the mrna as being intact. Required for mrna export from the nucleus and translation of the mrna. Almost all eukaryotic mrnas end with a long (~300 base) polya tail. Primary transcript: 5" ------------------------------- uaa -----------------30 base signal---3" At the end of the message there is a signal sequence at the end of the transcript that cleaves the mrna and adds the 300 base polya tail. Marks the 3" end of the mrna as being intact. Both of these signal together indicate that the mrna is intact as a whole. Protein encoding sequences (exons) are interrupted by noncoding sequences called (introns) Introns are "spliced" out of the primary transcript to give the mature mrna. Human b-globin gene - 200,000 nucleotide pairs gene.

Related Questions

Please help on these. Thank you!

Question 1

Which of the following is NOT a channel in the RNA polymeraseenzyme?

		RNA exit channel
		DNA entry channel
		DNA exit channel
		Nucleotide exit channel

Question 2

A promoter region upstream of a bacterial gene typically has thesequence TTGACA in the -35 position and TATAAT in the -10 position.If there was a 5 bp insertion at the -40 position, such thateverything downstream was shifted (ie: the "-35 element" is now atthe -30 from the transcription start site), which of the followingwill occur?

		Sigma protein will not bind and so no transcription willoccur.
		RNA polymerase will not bind and so no transcription willoccur.
		Sigma protein will bind to its target sequences and sotranscription will start 5bp downstream from the originaltranscription start site.
		Sigma protein will bind as usual and transcription will startappropriately at the transcription start site.

Question 3

A person has a mutation that prevents TFIIH from being produced.Which of the following outcomes will occur?

		No transcription because TFIID will not be able to bind.
		No transcription because the DNA strand will not be opened.
		Transcription will occur, but it will not be in the correctposition.
		Transcription will occur as usual.

Question 4

There are 4 rRNAs produced to make both subunits of theribosome. How many transcripts are required to produce these 4rRNAs?

		1
		2
		3
		4

Question 5

True or False: the 5' 7m-Gppp cap is attached to the start codonof the mRNA.

		True.
		False, the cap is attached to the 5'-untranslated region.
		False - the cap is attached to the 3'-untranslated region.
		False, the cap is attached to the polyA tail.

Question 6

During the splicing mechanism, which of the following joins twoexons together?

		A 2'OH attacks a 5' phosphate
		A 5' phosphate attacks a 2'OH
		A 3'OH attacks a 5' phosphate
		A 5' phosphate attacks a 3'OH Question 7 After their experiment in Neurospora, Beadle and Tatum concludedthat each single genes code for single enzymes. Do you agree withtheir statement, why or why not?

burgundyhedgehog579

Biochemistry 2280A Lecture Notes - Lecture 18: Nuclear Pore, Snrnp, Branch Point

Document Summary

Get access

Related Questions