L9. Bacterial Genetics

Question 1

what is transformation?

Answer 1

dna goes into another bacteria and now it has more power! (resistance can spread this way)

Question 2

what is conjugation?

Answer 2

bacterial sexual act

where pili represent the penis inserted from F+ bacterial cell into the neighboring F- bacterial cell

plasmid is transferred

now the neighboring cell is also F+ (can inject other bacterial cells)

Question 3

What is transduction?

Answer 3

spread of bacterial DNA through the action of a phage (virus)

Question 4

what is a transposon?

Answer 4

“jumping DNA” jumps b/w DNA molecules once inside a cell

Question 5

What is homologous recombination

Answer 5

the process by which a piece of DNA is incorporated into the chromosome

Question 6

what are Griffith’s transformation experiments?

Answer 6

an experiment which proves the concept of bacterial transformation

injected dead virulent strains togehter with live non virulent strain -> led to death of mice
conclusion: the non virulent strain was transformed

Question 7

what is an F plasmid?

Answer 7

contains genes needed to conduct “conjugation” in bacteria

Question 8

what is HFr?

Answer 8

a plasmid containing fertility factor has integrated into chromosome.
- this chromosome now has the ability to quickly integrate a copy of its HFr genes when it comes in contact with a normal cell

Question 9

what is OriT?

what is epidome?

Answer 9

OriT - region where a single strand break of DNA (allows the transfer of 1 strand of dna into another cell)

an integrated plasmid is called an epidome

Question 10

conjugation b/w HFr and F-

Answer 10

wont get transfer of the entire genome, only gonna get the frst few genes trasnferred not the entire genome

Question 11

what is a lytic attack?

Answer 11

process during which bacterial dna gets cleaved and some of it enters the bateriophages DNA

• can now perform transduction!

Question 12

virulent vs temperate phage?

Answer 12

virulent phage - infects bacteria, reproduce, lyse the bacteria and enter other bacteria

temperate phage - do not immediately induce lysis, at some poitn can get activated and cause lysis

Question 13

define prophage and lysogenic bacteria

Answer 13

prophage - integerated temperate page genome

lysogenic bacteria - bacteria that have a prophage integrated into their genome

Question 14

what is specialized transduction?

Answer 14

generalized transduction - cleaved bacterial dna accidentally enters lytic phage dna

specialized transduction - phage DNA is excised while taking bacterial DNA adjacent on both sides to it)

bacteria that are transduced this way:
ABCDs
strep A
botulinum
cholera
diptheria
shiga

Question 15

what are the two classes of transposons?

Answer 15

class 1: retrotransposons
-> copy and paste

Class 2: DNA that moves directly from one space to the other
-> cut and paste

Question 16

what type of repression is lac operon controlled by?

Answer 16

catabolite repression - positive control of lac operon

• > when you have glucose, metabolism of other sugars is repressed!
• > high cAMP signals low glucose -> enhanced production of genes that metabolize other sugars like lactose! (through CAP)

Question 17

What is an exogenote?

Answer 17

imported bacterial genes on short linear pieces of DNA