Skip to main content
Back

Bio 201 Lessons 10-11

Control buttons has been changed to "navigation" mode.
1/90

  • What are the 3 stages of transcription?

    Initiation, Elongation, and Termination

  • Bacteria or Eukaryotes: RNA polymerase binds directly to the DNA of the promoter

    Bacteria

  • Bacteria or Eukaryotes: Transcription factors first bind the DNA of the promoter to help orient the RNA polymerase

    Eukaryotes

  • Bacteria or Eukaryotes: RNA polymerase needs a primer to begin

    Neither

  • Bacteria or Eukaryotes: A conserved "consensus" sequence orients the transcription start site of a gene

    Both

  • Bacteria or Eukaryotes: RNA polymerase adds to the 3' OH of a growing RNA transcript

    Both

  • Bacteria or Eukaryotes: There are three major kinds of RNA polymerases for the cell

    Eukaryotes

  • Bacteria or Eukaryotes: Translation can begin as soon as the 5' end of the mRNA is synthesized by RNA polymerase

    Bacteria

  • Bacteria or Eukaryotes: A poly A site is involved in transcription termination

    Eukaryotes

  • Sequences that are largely the same across species and indicate a vital function of life

    Conserved Consensus Sequences

  • Where are conserved consensus sequences located in promoters?

    Upstream from the transcription start site

  • What are the bacterial promoters?

    -35 and -10

  • What are the eukaryotic promoters?

    TATA Box, GC Rich Box, and CAAT Box

  • Where is the 5' end of a gene (coding strand) located of the transcription termination site?

    Upstream

  • Elongation by RNA polymerase happens in what direction?

    From 5' --> 3'

  • How many RNA polymerases are in bacteria?

    1

  • Enzyme in eukaryotes that transcribes large ribosomal RNA (rRNA)

    RNA Polymerase I

  • Enzyme in eukaryotes that transcribes mRNA and various small nuclear RNAs

    RNA Polymerase II

  • Enzyme in eukaryotes that transcribes tRNA and small rRNA

    RNA Polymerase III

  • Why is translation coupled to translation in bacteria?

    There is no processing or compartmentalizing in a bacterial cell

  • How does transcription end in bacteria?

    Termination sequence is transcribed and the secondary structure of the mRNA results in RNA polymerase detaching from the DNA and mRNA

  • How does transcription end in eukaryotes?

    mRNA is clipped free from RNA polymerase down stream from the polyadenylation signal sequence

  • True or False: Different strands of the double helix DNA are used as the template for different genes

    True

  • What determines which strand is used as the template strand for a gene?

    The location of the promoter

  • Where is the promoter located on the gene?

    On the 5' end of the gene (coding strand)

  • What direction does RNA polymerase move in?

    Moves downstream or away from the promoter. Towards the transcription start site

  • Elements present on the same molecule of DNA as the gene they regulate

    Cis-Regulatory Elements

  • Elements that can regulate genes distant from the gene from which they were transcribed

    Trans-Regulatory Elements

  • True or False: Some sequences in the gene's promoter are more important than others in regulating transcription

    True

  • True or False: A promoter is not an example of a cis-regulatory element

    False

  • What factors serve as trans-acting elements in eukaryotes?

    Transcription factors and subunits of RNA polymerase

  • 5' cap or 3' poly-A tail: Prevents degradation of mRNA

    Both

  • 5' cap or 3' poly-A tail: Facilitates export of mRNA out of the nucleus

    Both

  • What does the 5' cap increase the efficiency of?

    Polyadenylation and splicing of mRNA

  • What does the 5' cap help target? What does this enhance?

    Helps target the mRNA to ribosomes and enhances the translation of mRNA

  • Regions of RNA that will be expressed (translated into amino acid sequences)

    Exons

  • Intervening sequences that are not translated into amino acid sequences

    Introns

  • What allows snRNAS to recognize specific sequences within introns?

    Complementary Base Pairing

  • What type of molecule in the spliceosome catalyzes the reaction of cutting out the introns and splicing together the exons?

    RNA

  • What happens if there is a mutation in the splice site?

    A shorter protein is created as the intron gets translated resulting in a premature stop codon occurring either inside the intron or via a frameshift within the exons

  • How do small RNAs in the spliceosome initiate the splicing of the pre-mRNA?

    By base pairing to specific sites along the intron

  • What are 3 characteristics that describe the AmpR gene?

    Selective Marker, Genetic Selection, Transformation Checkpoint

  • What are 3 characteristics that describe the LacZ gene?

    Reporter Gene, Genetic Screening, Ligation Checkpoint

  • What are 3 characteristics that describe the E.coli Origin of Replication?

    A-T Rich Region, Molecular Cloning, Replication Start

  • What are 3 characteristics that describe the Multiple Cloning Site?

    Inside of LacZ gene, EcoRI Recognition Sequence, Ligation Site

  • Sequence of nucleotides near the start of an operon to which an active repressor can attach

    Operator

  • Protein that inhibits gene transcription; binds to the operator, preventing RNA polymerase from binding and transcribing genes

    Repressor

  • Where does the repressor bind to?

    Promoter

  • Region of DNA that codes for a series of functionally related genes under the control of the same promoter; consists of a promoter, an operator, and a coordinately regulated cluster of genes whose products function in a common pathway

    Operon

  • What components make up an operon?

    Promoter, operator, and cluster of genes

  • Gene that encodes for a protein that controls the transcription of genes

    Regulatory Gene

  • Sequence with the most common nucleotide at each position

    Consensus Sequence

  • Costs cells less energy

    Economical

  • How much of a protein is produced per unit of time

    Level of Expression

  • "On" and neither repressed nor activated

    Basal

  • "Off" or lower than basal; some regulatory protein is decreasing the amount of transcription

    Repressed (negative regulation)

  • "On" or higher than basal; some regulatory protein is increasing the amount of transcription

    Activated (positive regulation)

  • One subunit of RNA polymerase that recognizes the promoter

    Sigma Factor

  • Regulation that changes the shape of the protein and possibly the function

    Allosteric Regulation

  • True or False: There is no definitive rule for what effect a ligand binding to a protein will have

    True

  • Small molecule that binds to a protein away from the business end and causes a change in shape

    Ligand

  • What happens when we bind to allolactose?

    The lac repressor releases the lac operator

  • What happens when we bind to cAMP?

    The CRP protein binds to its cis-element

  • What is the result of the lac operon promoter not being the greatest?

    Anything that helps stabilize RNA polymerase will increase the rate of successful transcription as CRP binds near the promoter and helps RNA polymerase stick long enough to get started

  • True or False: Basal expression includes repressors and activators

    False

  • What components does basal expression include?

    RNA polymerase and the promoter

  • True or False: Basal expression can be different for different genes

    True

  • What determines the level of basal expression for a gene?

    How well RNA polymerase binds to the promoter

  • If a promoter has a sequence that is similar to the consensus sequence, what does this mean?

    RNA polymerase binds more efficiently leading to higher rates or transcription initiation

  • How many translation start and start sites are in a gene?

    1 translation start and 1 translation stop

  • How many levels of expression does the trp operon have?

    2

  • When tryptophan is absent, what is the level of expression for the trp operon?

    Basal

  • When tryptophan is present, what is the level of expression for the trp operon?

    Repressed

  • How many levels of expression does the lac operon have?

    3

  • When lactose is absent, what is the level of expression for the lac operon?

    Repressed

  • When both lactose and glucose are present, what is the level of expression for the lac operon?

    Basal

  • When lactose is present and glucose is absent, what is the level of expression for the lac operon?

    Activated

  • Cis or Trans Regulatory Element: Lac Operator

    Cis

  • Cis or Trans Regulatory Element: CRP

    Trans

  • Cis or Trans Regulatory Element: RNA Polymerase

    Trans

  • Cis or Trans Regulatory Element: Trp Repressor

    Trans

  • Cis or Trans Regulatory Element: CRP Binding Site

    Cis

  • Cis or Trans Regulatory Element: Trp Repressor

    Trans

  • Cis or Trans Regulatory Element: Promoter

    Cis

  • Cis or Trans Regulatory Element: Trp Operator

    Cis

  • Lac or Trp Operon: Repressor is allosterically regulated

    Both

  • Lac or Trp Operon: Operon's gene products are needed to build a molecule

    Trp

  • True or False: RNA polymerase reads a template DNA strand from 3' to 5' in both bacteria and eukaryotes

    True

  • What orientation does the ribosome read mRNA in?

    5' to 3'

  • Human cells with different phenotypes all have the same _______ but must have different _______

    Control elements; transcription factors