BIO 202 Exam #3 Bradley University

Vertical gene transfer

Parent to daughter

Horizontal gene transfer

Passing bacteria to one another

DNA

Includes traits for antibiotic resistance

RecA gene

DNA recombination

Genome

All DNA of the cell

The genome includes:

- chromosomes

- plasmids

- viral DNA

- transposons

Out of the genome, which elements are considered "needed for survival"?

Chromosomes

Out of the genome, which elements are considered "accessory DNA"?

Plasmids, viral DNA, and transposons

Polymerase chain reaction

DNA replication in a test tube

How many copies of DNA are made using polymerase chain reaction?

Billions

In the central dogma, going from DNA to DNA is called:

Replication

In the central dogma, going from DNA to RNA is called:

Transcription

In the central dogma, going from RNA to proteins is called:

Translation

Is DNA temporary or permanent?

Permanent

Where do mutations occur?

DNA

What are RNA and proteins considered to be within the central dogma?

Hardwired

Is RNA made in abundance or as needed?

As needed

Is RNA temporary or permanent?

Temporary

MRNA

messenger RNA, template

tRNA

Transfer RNA, bring amino acids to the ribosomes

rRNA

Ribosomal RNA, a part of the ribosome

Genetic code

The relationship of amino acids to codons

Constitutive?

Always "on"

Operon

Grouped genes transcribed from a single promoter

What are the 4 mutations?

Silent, missense, nonsense, and frameshift

Silent mutation

No phenotype change (THE ONE BIG FLY)

Missense mutation

Altered phenotype (THQ ONE BIG FLY)

Nonsense mutation

subsitution of wrong nucleotide into DNA that produces an early stop codon (THE ONE)

Frameshift mutation

Non-functional (THE ONE QBI GLF)

Are spontaneous mutations purposeful?

They are NOT purposeful

What are the 3 R's in spontaneous mutations?

Replication, random, rare

Mutations can be connected to the concept of

Survival of the fittest

Where does vertical and horizontal gene transfer occur?

INTERcellular

Conjugation

Cell to cell transfer of bacterial DNA mediated by plasmids

How much DNA is transferred with conjugation?

LOTS

Transformation

uptake of DNA from environment, IF COMPETENT (only some cells)

Does transformation use horizontal or vertical gene transfer?

Horizontal gene transfer

Transduction

Transmission of bacterial DNA by a bacterial virus

Does transduction use horizontal or vertical gene transfer?

Horizontal gene transfer

Which method of horizontal gene transfer can create toxic bacteria? (Ex: botulism/diptheria)

Transduction

DNA can recombine if....

It is homologous

Phage conversion

transfer of exotoxin genes by lysogenic bacteriophage

Does conjugation use horizontal or vertical gene transfer?

Horizontal gene transfer

Conjugation includes 2 types of cells, what are they?

Donor and recipient cells

Hfr stands for...?

High frequency of recombination

What can Hfr do?

They can mediate their own transfer and mediate transfer of chromosomal genes (cell to cell)

Homology refers to what adjective?

Homologous

Homologous

Similar in DNA sequence

R-factor

When the plasmids have resistance genes

Generalized transduction

Random "mis-pack" of chromosomal DNA during the lytic cycle

What gene does generalized transduction require?

RecA gene

Generalized transduction

What does this diagram depict?

Specialized transduction

Incorrect incision of lysogenic DNA virus w/ chromosomal DNA

Transponsons are nicknamed...

Jumping genes

Transponsons are

DNA sequences that reshuffle the "genetic deck"

Can Transponsons transfer themselves from cell to cell

No, which complicates the horizontal gene transfer process

Genetic recombination

The breakage and reunion of the same DNA molecules

What is necessary for genetic recombination?

RecA genes

Antibiotics

Specific, naturally occurring compounds that inhibit/kill specific microbes at low concentrations

Did we create antibiotics?

No, we have adapted them over the years

Antibiotic resistance

The ability of bacteria + other microorganisms to resist the effects of an antibiotic to which they were once sensitive

______ is resistant to _______

Bacteria —> Drug

One goal of antibiotic therapy

Limit the course of the disease

Second goal of antibiotic therapy

Prevent pathogen drug disease

Survivors = ?

1/"dose"

Dose = ?

Concentration x Time

Most antibiotics are

Antibacterial

selective toxicity

poisonous in prokaryote cells

what is the general rule concerning selective toxicity?

more selective toxicity, less side effects

what type of drugs can you describe as narrow/broad?

anti-bacterial drugs ONLY

Narrow spectrum of activity

g+ OR g- (or a specific bacteria)

Broad spectrum of activity

g+ AND g- bacteria

First target of action: Cell Wall

mess up peptidoglycan synthesis

What does the Target of Action: cell wall affect in prokaryotes?

peptidoglycan

What does the Target of Action: cell wall affect in Fungi?

chitin

What drugs affect cell wall synthsis?

B-Lactam drugs and Non-B-Lactam drugs

"Natural" penicillin

B-Lactam drug that affects cell wall synthesis

Semi-synthetic penicillins

B-Lactam drug that affects cell wall synthesis

Cephalosporins

B-Lactam drug that affects cell wall synthesis

Vancomyocin

Non-B-Lactam drug that affects cell wall synthesis

Caspofungin

Non-B-Lactam drug that affects Chitin synthesis in Fungal cell walls ONLY

What gram reaction are "natural penicillins" effective against?

Gram Positive bacteria

What spectrum of activity do "natural penicillins" have?

narrow

Do "natural penicillins" cause hypersensitivity in humans?

yes, they can cause allergic reactions

What does the B-Lactam ring look like in active penicillin?

the B-Lactam ring is there, and complete

What does the B-Lactam ring look like in INactive penicillin?

there is no B-Lactam ring

Are cephalosporins narrow or broad spectrum?

broad spectrum

How do humans take Cephalosporin?

orally

Has Cephalosporins been adapted?

yes, 5-6 new generations have been created

Vancomyosin is useful in treating what disease?

MRSA

Is Vancomyosin a B-Lactam drug?

No, it is B-Lactamase resistant

Does Vancomyosin have a narrow or broad spectrum?

narrow spectrum (specifically Gram Positive Bacteria)

How does Vancomyosin work?

It inhibits the cross-linkage of peptidoglycan in a prokaryotic cell wall

Do "Penicillin Class" drugs bind the enzyme that creates a cross linkage, or inhibits it?

They bind the enzyme that creates a cross-linkage

Anti-TB agents are _____ line drugs

First

Do Anti-TB drugs treat quickly or slowly?

very slowly because the bacteria also grows very slowly

Isoniazid

Anti-TB drug, most potent

Ethambutol

Anti-TB drug

Pyrazinamide

Anti-TB drug

Why are anti TB drugs given in combination?

To prevent antibiotic resistance