Microbial Genetics, Pt 2: Regulation, Exchange Of Dna, Biotechnology

Front 1

Promoter

Back 1

where RNA polymerase binds upstream of coding region of gene to initiate transcription

Front 2

coding region

Back 2

where translation starts (AUG)

Front 3

one

Back 3

sometimes there's is only how many genes associated with a promoter?

Front 4

operon

Back 4

- a set of genes transcribed from the same promoter
- only found in prokaryotes

Front 5

constitutively

Back 5

~60-80% of genes are what expressed ?

Front 6

regulated

Back 6

genes that are not constitutively expressed are what in response to changes in the environment

Front 7

repression and activation

Back 7

transcription is regulated in what two ways?

Front 8

repressor

Back 8

inhibits transcription, often by blocking RNA polymerase from binding to the promoter

Front 9

operator

Back 9

the region the repressor binds to

Front 10

repressor

Back 10

with this, repressor binds operator and blocks RNA polymerase from initiating transcription

Front 11

induction

Back 11

turns on transcription of genes being repressed

Front 12

inducer

Back 12

- binds to the repressor, causing it to fall off operator and allow genes to be expressed
- often a signal that substrate of enzymes is present

Front 13

promoter

Back 13

positive regulators help recruit RNA polymerase to what?

Front 14

activator

Back 14

- without this, RNA polymerase has trouble binding to weak promoter
- causing transcription to not occur

Front 15

activators

Back 15

- help recruit RNA polymerase to the promoter activating transcription
-help make enzymes only when their substrate is present

Front 16

transcription

Back 16

with activator, activator helps RNA P bind and initiate what?

Front 17

three proteins

Back 17

how many proteins do the lac operon genes encode that use the sugar lactose as a carbon and energy source ?

Front 18

glucose

Back 18

- the best source of energy
- feeds straight into glycolysis
- reflected better in growth rate
- if cells had a choice it would choose to use this first and then make proteins use lactose

Front 19

no lactose is present

Back 19

the cell doesn't want to waste energy making the lactose enzymes/transporter, this happens when?

Front 20

lactose is present

Back 20

-cells sense it
- allolactose is a form of it and an inducer

Front 21

allosteric inhibition

Back 21

binds to Lacl and blocks it from binding to the operator

Front 22

lactose inducer

Back 22

- with this, repressor is not bound
- however, RNA polymerase also needs CAP (activator) to help it bind and initiate transcription

Front 23

CAP activator is inactive

Back 23

- high glucose = low cAMP = ...
- RNA polymerase still can't initiate lac transcription
- cell uses glucose instead of lactose

Front 24

CAP activator is active

Back 24

- low glucose = high cAMP = ...
- CAP helps RNA polymerase bind and start lac transcription
- cell uses lactose

Front 25

small regulatory (sRNA)

Back 25

- one type of cell RNA
- small
- unlike mRNA, most do not encode information to make proteins
- huge role in cell survival, health, and disease
- recent significance

Front 26

negative

Back 26

what type of regulating sRNA often block translation by inhibiting ribosome binding to the mRNA

Front 27

positive

Back 27

what type of regulating sRNA often enhance translation by stabilizing mRNA or helping the ribosome bind

Front 28

mutant

Back 28

organism that has the mutation

Front 29

wild-type

Back 29

- the 'normal' strain of a bacterium isolated from nature
- doesn't have a given mutation

Front 30

genotype

Back 30

- the genetic (DNA) make-up of an organism
- the information that codes for all its particular characteristics

Front 31

phenotype

Back 31

- manifestation of an organisms genotype
- actual, expressed properties, functions, behaviors

Front 32

1) make enzyme work faster/more efficiently
2) antibiotic resistance

Back 32

what are the beneficial parts of mutations?

Front 33

lose function of important protein

Back 33

what is a harmful effect of mutations

Front 34

point mutation

Back 34

- type of mutation
- a single nucleotide base pair in the DNA is replaced with a different one
- a.k.a. base pair substitution
- often due to substitution errors during DNA replication

Front 35

frameshift mutation

Back 35

- type of mutation
- insertion or deletion of one or more nucleotides in the DNA
- completely changes an amino acid sequence = BAD

Front 36

silent mutation

Back 36

- type of point mutation
-substitution results in codon that still encodes for the same amino acid
- not affect phenotype

Front 37

silent mutation

Back 37

- due to degeneracy of genetic code
- e.g. UAU ➡UAC
- both encode for tyrosine so protein is unaffected

Front 38

missense mutation

Back 38

- type of point mutation
- substitution results in codon that encodes a different amino acid in the protein

Front 39

nonsense mutation

Back 39

- type of point mutation
- substitution results in change to stop codon
- often result in truncated proteins = missing amino acids
- usually protein is nonfunctional

Front 40

spontaneous mutations

Back 40

- one way mutations occur
- random, rare errors made by DNA polymerase during DNA replication

Front 41

mutagens

Back 41

- one way mutations occur
- chemicals or radiation induce mutating to occur
- increase rate at which mutations happen vs spontaneous

Front 42

spontaneous and mutagen

Back 42

mutations are random. how do they happen?

Front 43

chemical mutagen

Back 43

- any chemical that can react with DNA to change its sequence
- altering base
- analog substitution for/look like base

Front 44

physical mutagen

Back 44

- result in lots of reactive ions and free radicals
- oxidize bases, resulting in errors in DNA replication/repair
- e.g. x-rays and gamma rays

Front 45

form new combinations of genes on the chromosome

Back 45

the exchange of genes/DNA fragments between two DNA molecules, it can do what?

Front 46

chromosomal DNA

Back 46

when foreign DNA is transfered into a cell, it can sometimes recombine with what of a similar sequence?

Front 47

recombination

Back 47

- expression of a different form/version of a given protein via what can allow bacteria to evade the immune system
- e.g. different forms of Salmonella and Neisseria

Front 48

vertical gene transfer

Back 48

genes are passed from an organism to its offspring

Front 49

horizontal gene transfer

Back 49

- genes are passed to other microbes of the same generation
- e.g. donor cell gives some of its DNA to a recipient

Front 50

transformation
transduction
conjugation

Back 50

what are the three main ways DNA can be transferred into bacterial cell

Front 51

transformation

Back 51

- DNA enters cell by its lonesome
- genes are transferred via free DNA in solution
- source: usually DNA from dead cells

Front 52

dead capsule

Back 52

DNA from what + cells give non-capsulated cells the ability to form capsules and cause disease

Front 53

transduction

Back 53

- bacterial DNA is accidentally packaged into bacteriophage capsid then transferred/introduced into recipient cell
- two types: generalized and specialized

Front 54

generalized transduction

Back 54

- type of transduction
- any bacterial genes are equally likely to be packaged into phage capsid

Front 55

specialized transduction

Back 55

- type of transduction
- only certain bacterial genes are transferred
- e.g. C. diphtheriae toxin

Front 56

conjugation

Back 56

- bacterial DNA is transferred directly from cell to cell
- occurs via plasmid
- requires cell-to-cell contact
- requires opposite mating types: donor (has plasmid) and recipient (does not)

Front 57

e.coli

Back 57

name an example of cojugation

Front 58

resistance (R) factors

Back 58

plasmids that carry genes that encode for antibiotic resistance

Front 59

virulence factor plasmids

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carry genes that aid in pathogens ability to cause disease
- toxins that harm host
- adhesions that allow pathogen to attach to host cells

Front 60

transposons

Back 60

- small, mobile fragments of DNA that can move from one region of a DNA molecule to another
- able to insert or transpose directly into the chromosome

Front 61

biotechnology

Back 61

- the use of microbes, cells, or cell components to make a product
- e.g. e. coli

Front 62

Biotechnology

Back 62

- used to produce genes
- plants and animals can be altered
- used for drug discovery and production, vaccine development, diagnostics assay, etc.