Studied by 10 people
Plasmid
A small circular DNA molecule found in bacteria. Nonessential DNA in bacteria that are not part of the bacterial chromosomes.
Plasmids can be transferred through direct physical contact between bacteria in a process known as conjugation, which helps bacteria share their antibiotic resistance genes with their neighbors.
How does a plasmid work to spread antibiotic resistance?
Conjugation
the transfer of plasmids between joined bacterial cells
Transduction
when DNA is transferred from one bacterial cell to another by a bacterial virus
Transformation
alteration of a bacterial cell's genome by the uptake of foreign DNA from the surrounding environment
rapid reproduction & mutation
why is genetic recombination in bacteria high?
Plasmids
where are antibiotic resistance genes in bacteria?
Conjugative
the f plasmid is a _____________ plasmid
cell wall
why is transformation not very efficient?
false
true of false: transformation must occur with plasmids
CaCl2
compound added to a bacterial cell in the lab to make it "competent"; makes cell wall easier to break through
dead cells
what may be a source of genetic material to be transferred via transformation?
pilus
bridge-like structure that forms between bacterial cells; plasmids can be transferred through
r plasmids
resistance genes are located on ____________
conjugation
antibiotic resistance is spread through _____________
F+
cells that contain the F plasmids are described as ______
F-
cells that do NOT contain the F plasmids are described as ______
vaccines
there is no cure for viruses, but you can be protected from them through _____________
hfr cells
a bacterial cell with a conjugated F plasmid integrated into its DNA molecule. They are cells with a high frequency of recombination
genomic DNA
hfr cells are capable of inserting their own ________________ into F- cells, which can lead to more recombination
F+ cell
the cell that is responsible for forming the pilus to begin conjugation
Virus
consists of nucleic acid enclosed by a protein coat
host
viruses need a ______ to undergo replication, transcription, or translation
obligate parasite
a parasite that obtains its nourishment by living in or on another organism
Bacteriophage
a virus that infects bacteria
bacteriophage
transduction is made possible when host DNA accidentally ends up inside of a _______________
lytic cycle
viral reproductive cycle in which a virus injects its amino acids into the host, degrades its DNA, hijacks it to produce its own DNA, and then kills the host cell.
lysogenic cycle
viral reproductive cycle in which the viral nucleic acids are added to the host cell and are copied along with the host cell's nucleic acids. host does not die.
recombination
_________ may occur with host's nucleic acids during the lysogenic cycle
Many bacteria use a system known as CRISPR-Cas to defend themselves against infection by viruses called phages. This system protects the bacterial cell by taking a short length of DNA from the phage and inserting this 'spacer' into its own genome.
Describe bacterial defenses against viruses
Dead S cells burst open and absorb the dealy gene
What happens to a bacterial cell when it dies?
selective vs non-selective medium
Selective media are used for the growth of only selected microorganisms.
Non-selective media allows of the growth of several different bactarial species
The first is known as conjugation- involves a direct physical interaction between two bacterial cells. One bacterium acts as a donor and transfers genetic material to a recipient cell.
The second means of transfer is called transduction. This occurs when a virus infects a bacterium and then transfers bacterial genetic material from that bacterium to another.
The last mode of genetic transfer is transformation. In this case, genetic material is released into the environment when a bacterial cell dies. This material then binds to a living bacterial cell, which can take it up.
Compare and contrast the major types of bacterial genetic transfer
Hfr cells possess a plasmid that replaces the bacterial chromosome entirely. F plasmids are integrated to their chromosomes.
How is a Hfr cell different?
When a temperate phage undergoes lysogeny, the phage gene becomes a part of the bacterial chromosome. Most phage genes in prophage are kept in an inactive state by a phage repressor protein encoded in one of the phage genes.
If a lysogen is infected with a phage of the same type as the prophage, then the repressor present within the cell from the prophage prevents expression of the genes of the infecting phage.
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What prevents a bacterial cell that is lysogenic for a temperate bacteriophage from being reinfected with a phage of the same type?
Selective media are used to select for the growth of a particular "selected" microorganism. It is a medium that allows the selection of one or more types of microorganisms. For example, if a certain microbe is resistant to a particular antibiotic, then that antibiotic can be added to the medium in order to prevent other organisms, which are not resistant, from growing.
What is selective media and provide an example of how it is used.
CRISPR
technological advancement that has made DNA manipulation significantly faster and cheaper
replica plating
when cells are grown on one plate and transferred to another; was done to prove that mutations occur randomly and unrelated to stimuli
one
prokaryotes have ______ RNA polymerase(s)
rna polymerase II
the rna polymerase that is used primarily in transcription
three
eukaryotes have _______ rna polymerase(s)
promoter
specific region of a gene where RNA polymerase can bind and begin transcription
initiation protein
binds to RNA strand; recruits RNA polymerase to come in and begin transcription
sigma factor
initiation protein in prokaryotes
promoter region
in prokaryotes, two consensus sequences make up the ______________
-10 and -35
where are the consensus sequences for the promoter region in prokaryotes?
TATA box
the very AT-rich middle of the promoter region in eukaryotes
-10 region
this part of the promoter region in prokaryotes is usually very A/T rich
26
the number of initiation factors that must bind to the promotor region in eukaryotes
enhancer
activator protein binds to ___________
the activator protein binds to the enhancer
in eukaryotes, the transcription factors cannot bind to the promoter region until...
eukaryotes
enhancer region is exclusive to ___________
5' to 3'
the direction in which RNA polymerase builds
promoter
each DNA strand has its own ___________ region for transcription
gene
the template strand can vary depending on the _________
terminator
in prokaryotes, this sequence causes a hairpin loop that dissociates RNA polymerase
hairpin loop and run of Us
key factors of termination in prokaryotes
rho-dependent termination
in prokaryotes, this is when the rho protein runs along the DNA strand in the opposite direction as the RNA polymerase, knocking it off the strand
prokaryote
eukaryote or prokaryote? no further processing is done to the mRNA following termination
AAUAAA
the polyadenylation sequence in eukaryotic termination
endonuclease
cuts the RNA polymerase out of the DNA strand 10-35 nucleotides after it reads the termination sequence
pre-mRNA
the product of transcription in eukaryotes
collinearity
when the linear order of the nucleotides in a gene = the linear order of amino acids to produce a gene
prokaryotes
collinearity is only associated with _____________
introns
sequence of DNA that is not involved in coding for a protein
exons
Coding segments of eukaryotic DNA
rna processing
in eukaryotes, when a 5' cap and 3' poly-A tail are added, and the introns are spliced out
mRNA
after processing following eukaryotic transcription, the result is ________
spliceosome
where RNA splicing takes place
snRNAs
found inside of the spliceosome; direct protein to recognize introns that must be cut out
untranslated regions
regions always left on the ends of the coding segment after mRNA processing
domain
part of the tertiary structure of the protein
independently
domains of a protein can exist __________ of one another
one gene one enzyme hypothesis
states that each gene is responsible for one enzyme, which affects a single step in a metabolic pathway
alternative splicing
the way in which selective introns can be cut out during the splicing process, resulting in various polypeptides that could be formed as a result
tRNA
type of RNA that translates each codon and brings the correct amino acid into the polypeptide sequence
anti-codon
each tRNA has an _________ that matches with the codon in sequence
aminoacyl-tRNA synthetase
enzyme that catalyzes the attachment of amino acids to the corresponding tRNA; reattaches amino acids to tRNA after they've lost them
ATP
used by aminoacyl-tRNA syntheyase to attach amino acids to tRNA molecules
wobble
flexibility in the base-pairing rules when it comes to the third nucleotide of a codon, in which a change in the base does not change the amino acid in sequence
ribosome
where protein synthesis occurs
monocistronic
eukaryotes are _____________, meaning that they can only translate one gene on one mRNA at one time
polycistronic
prokaryotes are __________, meaning they can translate multiple genes on one mRNA copy
5' cap
what elongation factors bind to to begin the translation process in eukaryotes
elongation factors
responsible for recruiting the ribosomal subunit and initiator tRNA in translation
AUG
where translation actually begins, and the large ribosomal unit is recruited
reading frame
the way in which codons are read in translation, 3 bases at a time; set by methionine
exit site
e site of a ribosome; where discharged tRNAs leave the ribosome
peptidyl site
p site of a ribosome; holds the tRNA that is carrying the growing polypeptide chain
aminoacyl site
a site in ribosome; holds the tRNA carrying the next amino acid in sequence
exit tunnel
part of the ribosome where the polypeptide chain is released
amino to carboxyl end
direction in which polypeptide chains are built
GTP hydrolysis
where the energy used to form peptide bonds comes from
dehydration synthesis
how new peptide bonds are made
stop codon
what causes release factors to stop translation
one
eukaryotes have _____ release factor(s)
three
prokaryotes have _______ release factor(s)
chaperone proteins
proteins that bind and release to hydrophobic regions of folding proteins to prevent them from folding onto themselves
chaperonin proteins
proteins that form cylindrical chambers where a folding protein can enter and form in an isolated region
GTP hydrolysis
when a mismatched anticodon is present at the A site, ________ is delayed
Note 
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