Topic Section 3: Lectures 10-16

The __________ is the main genetic element that is essential for the cell's survival.

chromosome

A polycistronic section of DNA (multiple genes) expresses multiple mRNA transcripts and eventually produces multiple proteins. True or False

false

T/F All mutations are bad and will result in deleterious effects on the cell, leading to death.

false

What part of the sequence below is TRANSCRIBED into an mRNA?

from the +1 (T) to the Rho-Independent Termination Sequence (also T codon chain)

A __________ is a specific genetic element within the chromosome that encodes the information to make a specific RNA

gene

The __________ is entire complement of genes in a cell

genome

What type of mutation(s) can lead to a change in the reading frame?

insertions; deletions (frameshift mutations)

Which of the following uses correct genetic nomenclature when referencing the gene for the lactose simple transporter?

lacY (All Italicized)

You are a researcher that is studying the facultative anaerobe Bacterium xyz. This bacterium does not encode the lacZYA operon and is naturally transformable (can uptake DNA). Which of the following genes would Bacterium xyz need to uptake to create a selectable mutation if you were growing the cells aerobically on a complex nutrient rich agar media with penicillin? How could you Change the Experiment to make Response "A" a Correct/Possible Response?

lacZYA (B-galactosidase); Grow cells in a Minimal Defined medium with Lactose as the Sole Carbon Source.

In __________ regulation, a repressor protein bings to the promoter region __________ RNA polymerase.

negative; inhibiting

A __________ is an autonomous DNA element that encodes non-essential genes

plasmid

In __________ regulation, an activator protein binds to the promoter region __________ RNA polymerase.

positive; recruiting

In the Hershey Chase experiments, researchers labeled phage __________ with radioactive sulfur, and phage __________ with radioactive phosphorus. After incubating the different phage samples with the bacteria, then separating the phage from the bacterial cells, they only ever observed radioactive __________ with the bacterial sample.

proteins; DNA; phosphorus

Drag the term to the appropriate box in the image.

replication; transcription; translation

Lacl and CAP are both constitutively expressed sensor transcriptional regulators. Lacl is a __________ that directly senses the levels of __________ in the cell. CAP is a __________ directly senses the levels of __________ in the cell.

repressor; lactose; activator; cAMP

The +1 site refers to what?

start of transcription

T/F The Zur protein recognizes specific sequences in the promoter region of the znuABCoperon and will only bind at this location, it will not bind the promoter region of the luxCDABE operon.

true

T/F The genes of the lacZYA operon code for proteins that will utilize the disaccharide sugar lactose.

true

What are Some Examples of a Mutation that Would/Could be Beneficial?

β-Lactamase (bla) Gene Allows for Survival in the Presence of that Specific Antibiotic

Which of the following statements describes an operon?

A set of genes transcribed from the same promoter.

What amino acid does the CGU codon encode?

Arg

Which of the following uses CORRECT genetic nomenclature?

Campylobacter jejuni; C. jejuni

Using your knowledge on Griffith's Transformation Experiments, which of the following describes a scenario where mice would succumb to an infection and die?

Challenge with a sample where live rough strains of the bacterium were incubated with heat-killed smooth strains

In the image below there is an alignment of 5 different promoter regions of 5 different genes in E. coli. Based on this alignment, which LOGO BEST describes the consensus sequence of these 5 promoter regions?

D

Which of the following best describes why E. coli exhibits diauxic growth when grown in a medium that contains glucose and lactose as the sole carbon and energy sources?

E. coli will first grow as it consumes all of the available glucose, it will then switch over to consuming the available lactose starting to grow again

Which one of the following group of organisms has the LOWEST mutation rate?

Eukaryotic Organisms (e.g. Humans)

Drag the regulatory definition to its correct location on the image describing that specific mechanism.

GENE A: No regulation (Constitutive) GENE D: Transcriptional Regulation GENE C: Translational Regulation GENE B: Post-Translational Regulation

Do you remember which Researcher(s) were the First to Discover and use Transformation to Understand basic Biological Processes?

Griffith was first to demonstrate transformation with smooth and rough cells of S. pneumo. Avery, MacLeod, McCarty used transformation to try to determine the transforming molecule

Do you remember which Researcher(s) used Transduction to Prove that DNA was the Transforming Molecule?

Hershey and Chase used the T2 Bacteriophage, E. coli, and radioactive DNA or protein to prove that DNA was the transforming molecule.

When will the LuxR protein be bound to the promoter region of the luxCDABEoperon?

High Cell Density

Why do you think E. coli Prefers to Consume ALL Glucose Before Consuming ANY Lactose?

It takes more energy to breakdown lactose than glucose. Glucose goes directly to glycolysis, but lactose must be cleaved first.

Which of the following uses correct genetic nomenclature when referencing the lactose simple transporter protein?

LacY

Why does E. coli prefer to use glucose prior to using lactose?

Lactose is a disaccharide that must be cleaved (requiring energy) before it can be used, Glucose can be used directly by the cell via glycolysis (with no additional energy input).

When will the Zur protein NOT be bound to the promoter region of the znuABCoperon?

Low Zinc

Two Separate Genes (not part of an Operon) are both Constitutively Expressed/Transcribed in the same bacterium. Does this mean that the Amount of mRNA Transcribed for each Individual Gene is the Same?

No

Under which of the following conditions is the LacI protein binding the operator of the lacZYA operon repressing transcription?

No Lactose / + Glucose

Which of the following is a type of point mutation where the mutation in the DNA results in a stop codon replacing a codon that would have encoded an amino acid?

Non-Sense Mutation

What strand of DNA does RNA Polymerase actually read to make an RNA transcript?

Non-coding strand

RNA polymerase directly reads the __________ strand of DNA in the 3' to 5' direction, synthesizing the RNA transcript in a 5' to 3' direction. The transcript is identical to the __________ strand of DNA, except T is replaced with U.

Non-coding; Coding

What type of Regulation specifically controls the ability for Zur or LuxR to interact with their respective promoters and control expression of their respective operons (znuABC and luxCDABE)?

Post-Translational Regulation

Recombinant DNA technologies have been used in which of the following?

Production of human insulin using E. coli; Production of biodegradable plastics using E. coli; Generation of pest resistant crops; Production of vaccines (All of the above use recombinant DNA technologies)

Zur, when bound to Zinc, acts as a Repressor by Binding the -10 and -35 DNA Sequence of the znuABC Promoter. What component of RNA Polymerase is Zur Directly Inhibiting from Binding to the -10 and -35 of the znuABC Promoter?

Sigma (σ)

Which type of transduction event relies on a prophage?

Specialized Transduction

Production of the ModE transcriptional repressor results in a decreased expression of modA transcript leading to a decrease in the amount of ModA produced.In the above statement, "ModE" is referencing which of the following?

The Protein

Mutation of Sigma Factor σ28 (aka: FliA) would result in which of the following?

The cell would be unable to perform chemotaxis in liquid media.

You are a researcher that is studying the facultative anaerobe Bacterium xyz. This bacterium does not encode the lacZYA operon and is naturally transformable (can uptake DNA). Which of the following genes would Bacterium xyz need to uptake to create a selectable mutation if you were growing the cells aerobically on a complex nutrient rich agar media with penicillin?

bla (b-lactamase)

The image below depicts a fluorescent reporter plasmid where the gfp gene is being expressed off the lac promoter (including all of the regions required for normal transcriptional control of the lacZYA operon). If you were to transform a bacterium with this plasmid, under which condition would you need to grow the cells in order for them to fluoresce green?

+ Lactose & No Glucose

nder which of the following conditions is the lacZYA operon fully activated?

+ Lactose / No Glucose

In the Meselson-Stahl experiment demonstrating DNA is replicated in a semi-conservative manner, after one round of DNA replication, how much of the double-stranded DNA products would be N15/N15 (Parental strand all N15 and newly replicated strand N15, both strands N15)

0%

You are studying the luxCDABE operon (image). When this operon is transcribed and translated, you would expect to produce _____ transcript(s), and _____ proteins.

1; 5

Identify the correct location on the DNA molecule of each of the following genetic motifs.Drag each term to it's correct location on the image.

5' -35 -10 +1 ATG TGA Terminator 3'

Based on the image below, which base is the mistake and will be removed by the Mut Mismatch Repair System?

C

Which of the following scenarios describes a horizontal gene transfer event?

Transfer of a plasmid via conjugation; Acquisition of new DNA via specialized transduction; Transforming a plasmid via electroporation in a microbiology research lab

Which of the following uses correct genetic nomenclature?

Vibrio cholerae (all italicized)

The Hershey and Chase experiment Involved Radiolabeled Bacteriophage (Either with 35S or 32P) and E. coli.If the bacteriophage could transfer antibiotic resistance to E. coli during transduction, would both 35S or 32P labeled phages be able to do this and make the E. coli antibiotic resistant?

Yes, both could do it.

You mutated the region of DNA upstream of lacZ, replacing the entire lac promoter with the znuABC Promoter. Under what conditions will lacZ be expressed/transcribed?

Zinc