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microbiology Flashcards

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1
Q

viruses are considered what?

A

obligate intracellular parasites

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2
Q

some viruses store ____ molecule in their capsid

A

ATP

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3
Q

Viral genome can be

A

DNA/RNA
Single/Double stranded
Linear/Circular

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4
Q

Viruses adaptations

A
  1. Carry very few genes
  2. rely on host-cell machinary
  3. encode for >1 protein in a given length of the host genome
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5
Q

How do viruses accomplish the encoding of greater than 1 protein in a given length of the host genome?

A

By utilizing more than 1 reading frame within a piece of DNA

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6
Q

Capsid

A

protein coat that surrounds the viral nucleic acid genome

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7
Q

Capsid head

A

contains the genome

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8
Q

Capsid tail fibers

A

attach to the surface of the host cell

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9
Q

Capsid Base Plate

A

attach to the surface of the host cell (check??)

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10
Q

Capsid Sheath

A

contracts using energy from ATP

injects genome into the host cell (check this??)

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11
Q

Envelope

A

Surrounds the capsid
Composed of phosopholipid, carbohydrates, proteins = from the host cell membrane and protein that is encoded by the virus

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12
Q

Naked Viruses can be distinguished by what?

A

They have NO envelopes

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13
Q

What is the first viral product?
What is its function?
Is an example of what?

A

hydrolase
degradation of host genome
early gene

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14
Q

lysozyme

A

destroys bacterial cell wall

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15
Q

Lysozyme can be found

A

in human tears, saliva, phages, mucas, milk

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16
Q

lysozyme is an example of a

A

late gene

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17
Q

without the cell wall

A

osmotic pressure no longer is counteracted –> bursting fo cell

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18
Q

naked virus infection is determined by

A

viral surface

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19
Q

Prophage

A

phage genome incorporated into bacterial genome

“pro - phage “ - used to indicate characteristics of the virus

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20
Q

Lysogen

A

Bacterial genome with prophage

“lysogenic bacterium” - term is used to describe the state of the bacterial cell

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21
Q

When a virus is considered a prophage, does it produce viral progeny?

A

No.

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22
Q

when a virus is considered a prophage what term would characterize its gene or gene expression?

A

silent except for the gene(s) that code for proteins that maintain prophage, such as for the phage-encoded repressor

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23
Q

How does a prophage silence its gene expression?

A

a phage-encoded repressor binds to specific DNA elements in phage promoters (operators)

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24
Q

Do viruses have promoters?

A

Yes

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25
Can viral gene expression be regulated by the virus?
Yes, example of phage encoded repressor
26
How do you think the expression of genes is regulated?
universally with as a few protein products and dna sequences required to regulate expression (remember viruses code for as few things as possible)
27
Transduction
process where the activation of a prophage leads to excision from the host genome
28
Animal viruses enter a target cell by
endocytosis
29
Productive cycle
Applies to animal viruses only Similar to lytic cycle Differs from lytic cycle in that it does not destroy host cell
30
How does an animal virus avoid destroying the host cell?
by budding instead of lysis
31
What property of the membrane allows an animal virus to exit without rupturing the membrane?
lipid bilayer can reseal itself
32
Provirus
dormant form of viral genome in lysogenic cycle of animal viruses (animal equivalent of a prophage)
33
RNA (+)
single stranded is essentially viral mRNA requires RNA(-) intermediate to generate new (+) strand genomes
34
RNA (-)
is essentially viral DNA equivalent (Note is not DNA itself_ | is template for mRNA production
35
Retroviruses
MUST encode for reverse transcriptase
36
reverse transcriptase
is a RNA-dependent DNA polymerase (takes RNA --> DNA) violates a big theme of molecular biology that information flows in a unidirectional manner from DNA --> RNA --> Protein.
37
List the 3 main retroviral genes and what they code for
gag - capsid polt - reverse transcriptase env - envelope
38
dsDNA virsuses
often encode enzymes for DNA replication and polymerization some induce host cell to enter mitosis can override cell inhibition for cell division --> cancerous cell
39
Bacteria do not contain what?
membrane bound organelles
40
What organelle does bacteria contain
ribosome
41
Bacterial genome is
circular double stranded DNA NOT associated with histones
42
We can differentiate between a bacterial genome and a human genome by?
bacterial genome would not have histones (proteins) in it while human genomes do.
43
Bacteria contain an extrachromosomal element called
a plasmid
44
Plasmid characteristics
circular piece of dsDNA aka extrachromosomal genetic elements may be capable of autonomous replication (replicating even though the genome is not)
45
Give the name for the following shaped bacteria: round rod-shaped spiral shaped
1. Round = Coccus / Cocci 2. Rod-shaped = Bacillus/Bacilli 3. Spiral-shaped = Spirochete, Spirillium, spirochetes, spirilla
46
The cell wall of bacteria is equivalent to what structure/process of animal cells that accomplishes the same function
cell wall of bacteria prevents lysis due to osmotic pressure | animal cells have pumps that pump out ions that accomplish the same function
47
Composition of bacteria cell wall
Peptidoglycan - Sugars & AA | contain D-Alanine (most AA are in L form)
48
What destroys peptidoglycan?
lysozyme | destruction of peptidoglycan results in a protoplast
49
Gram positive bacteria
thick peptidoglycan | Gram Stain - Dark Purple
50
gram negative bacteria
thin peptidoglycan outer layer of Lipopolysaccharide Gram Stain - Light Pink
51
where might enzymes that degrade antibiotics be found?
periplasmic space
52
endospores are formed by gram positive or gram negative bacteria?
gram positive (check??)
53
Endotoxin are a normal component of what type of bacteria?
Gram Negative
54
Where would an endotoxin be located on a gram negative bacteria
outer membrane
55
Are endotoxins inherently posionous? How do they cause us to get sick?
No. | They cause a severe immune reaction
56
Capsule
sticky layer of polysaccharide. Surrounds bacterial cells & can also surround bacterial cell colony enables bacteria to adhere to smooth surface Capsule is a form of virulence
57
Virulence
evades immune system
58
Flagella
filaments | motility
59
structural components of a flagella:
filament, hook, basal structure
60
basal structure
anchor flagellum to the IM & OM of Gram negative bacteria | serve to rotate the rod & rest of attached flagellum in CW or CCW
61
describe the structure of eukaryotic flagella.
Eukaryotic cillia and flagella = 9+2 arrangement of microtubules. centrioles are 9+0 arrangement.
62
pili
long projections on bacterial surface involved in attaching to different surfaces include the sex pilius
63
sex pilius is involved in
conjugation
64
Fimbraie
smaller structures involved in adherence to surfaces
65
what bacterial structures are involved in adherence?
Fimbraie and Capsule
66
Chemoautotrophs
energy - organic molecule | carbon source - organic molecule
67
Photoheterotrophs
energy - sun | carbon source - organic molecule
68
Obligate anaerobes
Poisoned by O2
69
why are obligate anaerobes poisoned by O2
because they lack a certain enzyme required for the detoxification of free radicals (free radicals form spontanously in the presence of O2)
70
what is the electron acceptor in respiration
O2
71
what is the electron acceptor in fermentation? what is the byproduct of fermentation?
pyruvate Ethanol Lactate
72
Bacterial mechanisms for the acquisition of new genetic material are
1. transduction 2. transformation 3. conjugation
73
Carrying capacity is what? what is it specific for?
the max population @ stationary phase | specific for that environment
74
what is the prokaryotic flagella made from
flagellum
75
what is the eukaryotic flagella made from
microtubules
76
How many bacteria are produce per a spore? what does that inherently tell you about population growth?
1 bacterial cell per a spore | bacteria cannot increase in population through spore formation
77
germination
metabolic reactivation of endospore
78
Conjugation
F+ male --> F- female
79
F factor
single circular DNA transferred unidirectionally recombination --> integration
80
make cards for virulence, biofilms, read more about flagella
THIS IS A HIGH YIELD TOPIC YOU REALLY SHOULD LEARN AS MUCH AS YOU CAN IN REGARDS TO THIS TOPIC

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