BIOL 330 Lecture Notes - Lecture 9: Chromatin, Transcription Factor Ii F, Messenger Rna

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19 Oct 2016

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Rna: terminator- a sequence of dna that causes rna polymerase to terminate transcription, transcription unit- the sequence between sites of initiation and termination by. The transcription reaction has three stages: 1. Bacterial rna polymerase consist of multiple subunits: holoenzyme- the rna polymerase form that is competent to initiate transcription. Tata box), and another hexamer with a sequence similar to ttgaca centered at about -35 (-35 element) Individual promoters usually differ from the consensus at one or more position: promoter efficiency can be affected by additional elements as well. Up element- a sequence in bacteria adjacent to the promoter, upstream. Promoter efficiencies can be increased or decreased by mutations of the -35 element, that enhances transcription: down mutation decrease promoter efficiency. Rna polymerase in the promoter: the points of contact lie primarily on one face of the dna. Rna chain reaches about 10 nt in length. Bacterial rna polymerase terminates at discrete sites: there are two classes of terminators.

Related Questions

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

5. Alpha amanitin is a drug that binds RNA polymerase andprevents it from functioning in the cell (this is the compound thatis found in poison mushrooms). The reason people die when theyconsume alpha amanitin is:

a) Alpha amanitin prevents gene expression from occurring in thecell

b) DNA replication is directly inhibited by alpha amantin

c) Alpha amanitin binds tightly to the messenger RNAs that aremade in the cell, preventing translation

d) Alpha amanitin binds to nuclear pores preventing thetransport of messenger RNA into the cytoplasm

6. In order for transcriptional initiation to begin in E. colithe following elements are needed:

a) an origin and RNA polymerase

b) initiator protein and a promoter

c) the sigma subunit of RNA polymerase and an RNA template

d) RNA polymerase and a promoter

e) helicase and primase

Questions 7 and 8. You are studying two species of closelyrelated snakes, one species lives in sandy desert area and has paletan skin and the species lives in a volcanic rock area and has darkbrown skin. You a sequence the DNA from each type of snake anddiscover a gene encoding a protein that transports pigment into theskin cells. The pigment transporter protein is responsible for skincolor. When you analyze the DNA coding sequence of the pigmenttransporter from each snake you find these two DNA sequences (hashmarks have been added to indicate the reading frame):

pale tan snake: GCG/TTG/GAC/TGC/ACC (DNA template strand)CGC/AAC/CTG/ACG/TGG (complementary strand) dark brown snake:ACG/TTG/GAC/TGC/ACC (DNA template strand) TGC/AAC/CTG/ACG/TGG(complementary strand)

7. From these sequences you conclude:

a) that the amino acid sequence of the pigment transporters forthe two proteins are almost identical

b) that the amino acid sequence of the pigment transporters forthe two proteins are very dissimilar

c) that the amino acid sequence of the pigment transporters forthe two proteins are identical

8. Since the skin color is different in each snake, you concludefrom the sequence data above that:

a) the genetic code in the skin cells in each of these snakes isdifferent

b) the DNA sequence encoding the entire gene for pigmenttransporters in these two snakes is different

c) that one of the codons in the gene for the pigmenttransporter in these two snakes is different

9. You are analyzing eukaryotic cells that have been exposed tothe radioactive uracil. In most cells the radioactive uracil isinitially localized in the nucleus and then moves from the nucleusto the cytoplasm. However, you observe that in some cells theradioactive molecules stay in the nucleus and never arrive in thecytoplasm. This is most likely a defect in:

a) the transcription of the DNA

b) the processing of the mRNA

c) the translation of the RNA

d) the labeling of the RNA

e) the replication of the DNA

10. Which of the following is true of both eukaryotic andbacterial transcription? (select all that are true)
a) Transcription factors must bind the promoter before RNApolymerase initiates transcription

b) Messenger RNAs must be spliced before translation begins inorder to produce the appropriate gene product

c) During transcription only one DNA strand is used as atemplate to make the messenger RNA

d) Termination of transcription occurs when the RNA polymerasetranscribes a hairpin structure in the RNA followed by a string ofU

erinporpoise384

BIOCHEM QUESTIONS:

Question 1) (1.5 points) True or false: The initial native DNA is usually in an overwound state, making the initial strand separation during replication energetically favorable, with continued strand separation at the replication fork resulting in underwound DNA that is then fixed by DNA gyrase.

Question 2) (1.5 points) True or false: UV based DNA damage largely causes dimerization of C and T bases that are fixed by the NER DNA repair pathway.

Question 3) (1.5 points) True or false: There is no enzyme within humans that has a reverse transcriptase activity.

Question 4) (1.5 points) True or false: One reason why uracil is not observed in DNA is that deamination of cytosine would result in Uracil and therefore potentially changing a GC base bp to an AT bp after a couple of rounds of replication.

Question #5: (1 point) Which of these statements is correct about the RNA polymerase? a) It makes tRNA, mRNA and rRNA b) It uses an RNA template c) It uses ATP, CTP, GTP and TTP d) It requires a primer

Question #6: (1 point) RNA polymerase grows the RNA chain in the 3â to 5â direction. a) True b) False

Question #7: (1 point) The mRNA is copied from the template strand. The mRNA has the exact same nucleotide sequence of the non-template strand except for U instead of T. a) True b) False

Question #8: (1 point) Only a limited portion of the DNA strand is copied by RNA polymerase, and there are initiation and termination signals for transcription. a) True b) False

Question #9: (1 point) The hairpin loop is the only way to conduct transcription termination in Prokaryotes. a) True b) False

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BIOL 330 Lecture Notes - Lecture 9: Chromatin, Transcription Factor Ii F, Messenger Rna

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