Microbiology

Question 1

How do viruses function?

Answer 1

They rely on host machinery to survive and are without activity outside the cell.

Question 2

What is the structure of viruses?

Answer 2

A nucleic acid genome packaged in a protein shell, they are small and the exterior shell can’t expand to accommodate a larger genome

Question 3

capsid

Answer 3

protein coat surrounding the viral nucleic acid

Question 4

capsid head

Answer 4

where the genome is located

Question 5

tail fibers

Answer 5

attach to surface of host cell along with base plate

Question 6

sheath

Answer 6

injects genome into host through contraction using ATP

Question 7

envelope

Answer 7

surrounds capsid, derived from host cell membrane, acquired when viruses bud through host cell membrane

Question 8

adsorption

Answer 8

binding to the exterior of a bacterial cell

Question 9

penetration

Answer 9

injection of viral genome into host cell, aka eclipse

Question 10

lytic cycle

Answer 10

produces hydrolase, which degrades the host genome, and later on, lysozyme, which causes the host bacterium to burst after transcription and translation of the phage genome.

Question 11

lysogenic cycle

Answer 11

phage genome enters bacterial genome, making the host a lysogen. Viral progeny is not produced, but every time the host cell reproduces, the prophage is reproduced and eventually enters the lytic cycle.

Question 12

endocytosis

Answer 12

how most animal viruses enter cells, host cell engulfs virus and internalizes it.

Question 13

productive cycle

Answer 13

similar to lytic cycle but doesn’t destroy host cells.

viruses that infect animal cells

Question 14

sub viral particles

Answer 14

smaller and simpler than viruses, include prions and viroids

Question 15

prions

Answer 15

misfolded versions of proteins that already exist, can cause TSEs, which are fatal.

Question 16

viroids

Answer 16

consist of a short piece of circular single stranded RNA, have extensive self complementarity

Question 17

What are the tenets of cell theory

Answer 17

1. All living organisms are composed of one or more cells and their products
2. Cells are the monomer for any organism
3. New cells arise from pre existing living cells

Question 18

What distinguishes prokaryotes from eukaryotes

Answer 18

Prokaryotes don’t contain membrane bound organelles

Question 19

What are the types of prokaryotes

Answer 19

bacteria, archer, blue green algae

Question 20

what are the three recognized domains

Answer 20

bacteria, archea, eukarya

Question 21

polyribosome

Answer 21

ribosomes translating a single piece of mRNA, found in prokaryotes

Question 22

plasmid

Answer 22

circular piece of double stranded DNA which is much smaller than the genome, an extrachromosomal genetic element

Question 23

conjugation

Answer 23

bacterial exchange of genetic information

Question 24

What is the bacterial cell wall composed of

Answer 24

peptidoglycan

Question 25

gram positive vs gram negative bacteria

Answer 25

gram positive stain strongly and gram negative stain weakly. Gram negative bacteria has a periplasmic space, which offers it more protection from the environment.

Question 26

capsule

Answer 26

sticky layer surrounding bacterial cell that makes bacteria more difficult for immune system cells to eradicate.

Question 27

flagella

Answer 27

involved in bacterial motility

Question 28

What is part of the structure of flagellum

Answer 28

a filament, hook, and basal structure

Question 29

chemotaxis -

Answer 29

bacterial motion toward attractants or away from toxins via chemoreceptors

Question 30

pili

Answer 30

long projections on bacterial surface involved in attaching to different surfaces

Question 31

four types of bacteria

Answer 31

chemoautotrophs - build organic molecules from CO2 using chemical energy
chemoheterotrophs - require organic molecules such as glucose made by other organisms their carbon source and for energy
photoautotrophs - use only CO2 as a carbon source and obtain their energy from the Sun
photoheterotrophs. - get energy from the Sun but require an organic molecule made by another organism as their carbon source.

Question 32

wild type bacteria

Answer 32

possesses all the characteristics normal to that particular species

Question 33

auxotroph

Answer 33

bacteria that can’t survive on minimal medium, because It can’t synthesize a molecule it needs to live.

Question 34

obligate aerobes vs obligate anaerobes

Answer 34

need oxygen vs poisoned by oxygen

Question 35

binary fission

Answer 35

mode of replication in bacteria

Question 36

stages of bacterial reproduction

Answer 36

lag phase to log phase to stationary phase to death phase

Question 37

endospores

Answer 37

formed by gram + bacteria under unfavorable growth conditions

helps bacteria “Sleep through the bad times”

Question 38

three bacterial mechanisms of acquiring new genetic material

Answer 38

transduction, transformation, and conjugation

Question 39

F factor

Answer 39

key to bacterial conjugation, bacteria with F factor are male

Question 40

transduction

Answer 40

process by which a virus transfers genetic material from one bacterium to another

when lysogenic viruses take pieces of host DNA with them when they excise and transfer it to the next host

Question 41

retroviruses

Answer 41

inserts a DNA copy of its RNA genome into the DNA of the host cell it invades, changing the genome of the cell

the sequence of the nucleotide in the original viral genome will be the same as that of the transcribed mRNA

ex. HIV