BIOL240 Lecture Notes - Lecture 11: Trp Operon, Sigma Factor, Operon

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cyanhorse768

12 Jul 2017

School

University of Waterloo

Department

Biology

Course

BIOL240

Professor

Josh Neufeld

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Document Summary

Rna polymerase makes rna from dna: recognizes the genes to transcribe using a core enzyme and a sigma factor, uses different sigma factors (modular protein components) for recognizing different genes and initiating different gene transcriptions. Sigma factors guide rna polymerase to appropriate dna regions to begin transcribing: sigma factors (+ rna polymerase) bind to promoter regions on dna, sigma factor + rna polymerase = holoenzyme, promoter regions are -10 and -35 positions. Ribosomes (made of many ribosomal proteins + rrna) binds to mrna transcripts at the shine- delgarno sequence: this sequence orients the ribosome on the mrna strand to begin translating at the initial start codon. Initial start codon is downstream from the shine-delgarno sequence. Regulation allows microorganisms to respond to environmental stimuli: to respond to different available nutrients, expressing genes that can use those nutrients (esp with transport, enables specific metabolic processes (aerobic respiration vs fermentation, approx.

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

BIOL240 Lecture Notes - Lecture 11: Trp Operon, Sigma Factor, Operon

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