Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology > Ch. 5 > Flashcards

Ch. 5 Flashcards

(80 cards)

Start Studying
1
Q

genotype

A

genetic makeup influences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

phenotype

A

physiological and physical traits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

genomes

A

entire collection of genetic material in entire organism *our cells need instructions to fxn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are genes?

A

heritable units of genetic info. made up of genotype and phenotypes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

genetics

A

study of genes, their function, and how variations arise in genomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what genomes do cells have?

A

DNA genomes (determines phenotypes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what genomes do viruses have?

A

DNA or RNA genomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

chromosomes

A

tightly packaged DNA in nucleus in euks or loosely packaged in nucleoid region in proks *# of chromosomes do not necessarily contribute to how sophisticated the organism is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what do histones do in eukaryotes?

A

help organize DNA so it doesn’t get tangled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

histone-like proteins

A

organize genome into just 1-3 chromosomes = located in the nucleoid region.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

plasmids

A

pieces of DNA that exist outside of that chromosomal DNA; can exist in euks or proks; may be abx resistant in bacteria = advantage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are DNA’s structure and Function built from?

A

nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the three basic parts of nucleotides?

A

phosphate, sugar, and nitrogen base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

DNA structure

A

double helix (twisted ladder) *base pair “rungs” (pairs of nitrogenous bases) and “rails” sugar phosphate backbone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how is DNA built?

A

5’ to 3’ *5’ phosphate links to 3’ OH group *think antiparallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

3 parts of RNA

A

phosphate group, sugar (ribose), and nitrogen base (Adenine, Guanine, Cytosine, and Uracil)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

True or False: Uracil replaces Thymine in RNA

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

RNA structure

A

Often single stranded; can fold onto itself to form looping like structures as well as helical
3 types: messenger, transfer, ribosomal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

central dogma of molecular biology

A

genetic info flows from DNA to RNA to proteins that perform some function in the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

DNA replication

A

process by which a cell copies its genome before it divides and it involves unwinding DNA, copying DNA, rewinding DNA. Very fast and accurate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why is DNA replication important?

A

needed for cell division and many drugs work by inhibiting DNA replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

protein synthesis (gene expression)

A

creates gene products (proteins). Genes in DNA copied into RNA (transcription). Product- mRNA is used to build proteins (translation) *v imp for life! Many abx work by blocking this -> kills off cells *only parts of the genome is transcribed or translated, not entire genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

transcription

A

genes in DNA copied into RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

translation

A

mRNA is used to build proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
reverse transcription
RNA is used to make a copy of DNA
25
Where does transcription occur?
cytoplasm in proks and nucleus in euks
26
What do euks have to do before translation?
Euks have to process their mRNA before translation bc the mRNA have introns (non protein encoding parts of RNA) -> euks have to cut introns out -> put exons (protein coding regions) -> translation
27
Where do euks move RNA to during translation?
They move RNA from the nucleus to the cytoplasm
28
helicase
unwinds DNA helix
29
primase
builds RNA primers; multiple primers are required to build the lagging strand
30
DNA polymerase III
Main enzyme that copies DNA on the leading and lagging strand
31
DNA polymerase I
Replaces RNA primers with DNA; also has a role in DNA repair
32
Ligase
Forms phosphodiester bonds to seal nicks in the DNA sugar-phosphate backbone; important in DNA replication and DNA repair
33
Gyrase and Topoisomerases
relieve torsion stress that develops ahead of helicase as DNA unwinds
34
house-keeping genes
always on and needed for normal cellular functions
35
facultative genes
not always on and encoded in a response
36
step 1 of translation: initiation
ribosome attaches to mRNA and scans til it reaches a start codon (usually AUG) -> initiator tRNA carrying amino acid methionine enters ribo’s P site. *Translation can occur b4 transcription is complete in some proks bc no need for splicing and no need to move mRNA
37
step 2 of translation: elongation
tRNA enters A site -> peptide bond forms btw AAs transferring growing protein to tRNA in A site -> ribo translocates (shifts) down mRNA, tRNA in P site shifts to E site to exit ribo and tRNA in A site shifts to P site -> repeat cycle til stop codon reached
38
step 3 of translation: termination
ribo encounters stop codon -> termination factor enters ribo -> ribo releases the protein and detaches from mRNA. Next step: may need folding, trimming, adding factors before functioning
39
genetic code and amino acids
4 nucleotides in RNA and 3 nucleotides in a codon -> 64 unique codons
40
64 codons encode:
60 sense codons (code 20 standard amino acids), 1 start signal, and 3 nonsense codons (stop signals)
41
what does pre-transcriptional regulation regulate and impact?
regulates RNA production. impacts when and how often transcription occurs
42
transcription factors
allows control over protein synthesis; proteins that bind to promoters and recruit RNA polymerase
43
operons
collection of genes controlled by a shared regulatory element; found in euks and proks *think of these as coaches of a baseball team
44
operons contain 4 key parts
promotor: site where RNA polymerase binds to start transcription genes: 2 or more that encode proteins that work together toward a shared task repressor: blocks transcription operator: binds repressor to block transcription
45
inducible operons
OFF by default; certain conditions activate (induce) transcription *ex: lactose operon
46
repressible operons
ON by default; actively transcribed til they’re switched off (repressed) *ex: arginine operon
47
epigenome
collection of chemical changes to the genome
48
DNA methylation
control transcription of certain genes in certain cells. Addition of methyl groups to DNA. Prevents transcription In humans, when the patterns r altered, can be detrimental -> cancer or birth defects In bact, can coordinate DNA repair, can help cell respond to stress, can affect cell’s ability to cause disease, can protect bact from bacteriophages
49
quorum sensing
bact exist in communities and communicate using chemical messengers called autoinducers; sensing and responding to changes in bact community; allows bact to alter protein synthesis in response to changes in density of population
50
post-transcriptional regulation
impacts how often mRNA is translated into protein. - Altered mRNA stability: mRNA will have limited existence, it’s not v stable and won’t be able to exist for a v long time, which means it has a limited amt of time to b translated - Rate of mRNA splicing and export (in euks) - Small noncoding RNAs: limit psynth by binding to mRNAs using complementary base pairing to dec r8 of mRNA translation. Bind to mRNA, tag it for destruction OR prevent it from interacting w ribos needed to start translation process. - Riboswitches: mRNAs that hv built-in switches that help em ctrl psynth. Common in bact
51
mutation
change in genetic material of a cell or virus (can be neutral, beneficial, or harmful
52
substitution mutation
addition of incorrect nucleotides
53
insertion mutation
+1 nucleotides are added to the genome
54
deletion mutations
+1 nucleotides are deleted from genome sequence
55
silent mutations
no effect
56
missense mutation
new codon encodes for the wrong AA
57
nonsense mutation
result is stop signal instead of AA *v problematic
58
when do frameshift mutations occur?
when bases are inserted or deleted
59
when are insertion/deletion impacts often minimized?
when they are in multiples of 3
60
spontaneous mutation
naturally occurring due to error in DNA replication; introduce genetic variation
61
induced mutations
prompted by some environmental factor
62
what are mutant strains
cells carrying a mutation
63
what are wild-type strains
non-mutated cells
64
mutagens
increase rate of mutations
65
chemical mutagen
induce breaks in DNA, can modify bases, promote frameshift mutations *ex: asbestos, alcohol
66
physical mutagens
can induce DNA damage similar to chemical *ex: UV light, xrays
67
biological mutagen
induce genetic change through exchange of genetic material that can lead to new and different genetic combos in organisms *ex: transposons and certain viruses
68
carcinogens
mutation that causes cancer
69
DNA polymerase
proofread DNA and fix detected errors *error rate is v low BUT when rate of DNA damage outpaces rate of DNA repair -> mutations which can lead to death in single celled organisms like bact. In animals, the mutations can accumulate and manifest as cancers
70
vertical gene transfer
occurs when a cell passes genetic info to the next gen as a result of asexual or sexual reproduction
71
horizontal gene transfer
genetic info’s passed w/o cell division
72
plasmids -- horizontal gene transfer
often players in these events; can offer selective advantage to a cell by assisting w cell toxicity, protecting against abx, performing conjugation
73
F factor conjunction
A bact carries an F factor -> it builds a pilus bridge to attach to a neighboring cell and then transfers across the pilus -> pilus dissolves and both cells now contain F plasmid
74
Hfr strain conjunction
A bact has F plasmid integrated into its genome -> builds a pilus and attaches to a neighboring cell -> F plasmid and part of host chromosomal DNA transfers across pilus -> pilus dissolves
75
transformation
occurs when bacteria take up DNA from their environment; exogenous DNA crosses CW through absorption; hv to b competent (physiological state capable of transformation); can occur in lab or via dead bact cells or badly fragmented / ancient old DNA; *in euks, this is called TRANSFECTION
76
transposons
“jumping genes” *implications: can alter psynth, can change genetic sequences, can intro new genes, can cause mutations that lead to disease
77
retrotransposons
retrotransposons r copied into an RNA format b4 transcription -> reverse transcriptase uses the RNA to build a DNA copy -> the DNA copy is converted to a double stranded molecule -> copied transposon inserts into new spot in genome
78
DNA transposons: copy and paste mechanism
transposons copy and then paste themselves into new location. The original transposon remains in its original location
79
DNA transposons: cut and paste mechanism
DNA transposon isn’t copied before it’s excised and moved, which means a gap is left in the original location of the DNA transposon

Microbiology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions