Week 4: Viral Replication & Microbial Classification

Question 1

steps of viral replication

Answer 1

• Attachment
• Penetration
• Uncoating
• Synthesis
• Assembly
• Release

Question 2

attachment step

Answer 2

marks initial contact bw the virion and host cell

Question 3

viral specificity

Answer 3

specific interaction between virus and host cell

Question 4

viral glycoproteins located in

Answer 4

evelope & capsid

Question 5

penetration step

Answer 5

virion enters the host cell by endocytosis or fusion

Question 6

uncoating step

Answer 6

shedding of viral capsid

Question 7

synthesis step

Answer 7

genetic material is replicated and capsomeres are produced

Question 8

assembly step

Answer 8

characterized by the reassembly of complete virions after replication of capsomeres and genetic material

Question 9

release step

Answer 9

release of virion from the host cell by either cell lysis or budding

Question 10

synthesis of DNA viruses

Answer 10

• Viral DNA is used to make viral RNA. RNA are usually short segments of
template instructions used to synthesize proteins
• Proteins in the host cell read the RNA templates and synthesize viral proteins
• Newly synthesized viral proteins are used to copy hundreds, or thousands of
copies of Viral DNA
• Newly synthesized DNA and capsid proteins reassemble in the assembly stage prior to release from the cell

Question 11

synthesis of RNA viruses

Answer 11

RNA is used as a template to both synthesize new capsid proteins as
well replicated many times to create newly synthesized RNA molecules for viral
assembly & release

Question 12

synthesis of retroviruses

Answer 12

RNA is the genetic material, but use a unique replication process
• RNA is converted into DNA by reverse transcription
• Requires a unique enzyme to do this: reverse transcriptase
• DNA is then transcribed into RNA:
• RNA copies for the new viral particle genomes,
• Or, are translated into new capsid proteins

Question 13

taxonomy

Answer 13

the categorization of living things based on a hierarchy of relatedness

Question 14

as you move down a taxonomy hierarchy, grouping becomes

Answer 14

more related

Question 15

binomial nomenclature was introduced by

Answer 15

linnaeus

Question 16

species are assigned two names in the following format

Answer 16

Genus species

Question 17

phylogenetics

Answer 17

classify organisms based on genetic relatedness and shared ancestry

Question 18

3 domains of life

Answer 18

archaea, bacteria, eukarya

Question 19

bacteria

Answer 19

Prokaryotes; generally includes the bacteria that we’re most familiar with

Question 20

archaea

Answer 20

Prokaryotes that are structurally and functionally unique from Bacteria

Question 21

eukarya

Answer 21

Animals, plants, protozoa and fungi

Question 22

domain bacteria - aquifex/hydrogenobacter

Answer 22

Thermophiles – grow at extremely high temperatures (~95°C)

Question 23

domain bacteria - green nonsulpher bacteria

Answer 23

Also composed entirely of thermophiles, but don’t tolerate the extreme heats of the
Aquifex/Hydrogenobacter lineage
• Photosynthetic

Question 24

domain bacteria - radioresistant cocci

Answer 24

Resistant to very high doses of radiation
• Multi-layered cell wall combined with an outer membrane and excellent DNA repair functions
make this group highly resistant to radiation

Question 25

domain bacteria - spirochetes

Answer 25

Flexible helical shape | • Known to infect humans ex. Treponema pallidum the causative agent of syphilis

Question 26

domain bacteria - green sulpher bacteria

Answer 26

photosynthetic

Question 27

domain bacteria - flavobacteria

Answer 27

• Ex. Bacteroides gingivalis a strict anaerobe (cannot grow in the presence of oxygen) thrives below the gumline causing gingivitis

Question 28

domain bacteria - clamydiae

Answer 28

Obligate intracellular parasites – cannot grow unless inside the cytoplasm of an appropriate host cell

Question 29

domain bacteria - gram positive

Answer 29

Contains the Staphylococcus and Streptococcus sp. | • Significant category for human health

Question 30

domain bacteria - cyanobacteria

Answer 30

* Photosynthetic * Important players in a variety of ecosystems * Release large amounts of oxygen into the environment/ air * Nitrogen fixation supporting plant growth

Question 31

domain bacteria - proteobacteria

Answer 31

Contains the Gram-negative species • Highly variable in shape, metabolism and motility • Significant category for human health

Question 32

domain archea - extremophiles

Answer 32

* Prokaryotes living in extreme environmental conditions * Thermophile (heat) * Halophile (salt) * Acidophile (acid)

Question 33

archea characteristics

Answer 33

Usually have cell walls, but no peptidoglycan • Unique lipids in the plasma membrane • Protein synthesis more closely mimics the eukaryotic process • Methanogens are an important lineage

Question 34

domain eukarya consists of

Answer 34

protozoa, fungi

Question 35

protozoa

Answer 35

``` • Unicellular eukaryotes • No cell wall • Found in aquatic and moist environments • Complex life cyles ```

Question 36

protozoan life cycle

Answer 36

* Trophozoite – feeding and reproducing stage * Under favourable environmental conditions, the protozoa exists in this stage * Cyst – metabolically inactive * When environmental conditions are not ideal, the protozoa exists in this stage

Question 37

parasitic protozoans

Answer 37

Generally exist in the environment as cysts, when they enter a new host they develop into trophozoites where they feed and reproduce. New cysts are released back into the environment

Question 38

4 main types of protozoa

Answer 38

flagellates, amoebae, ciliates, apicomplexa

Question 39

fungi

Answer 39

Play an important ecological role by recycling nutrients in the environment • Many fungi have mutualistic symbiotic relationships with plant species; whereby the plant and the fungi benefit from living together, both receiving the nutrients they require to thrive

Question 40

2 types of fungal bodies

Answer 40

* Single celled (ex. yeast) | * Filamentous fungi

Question 41

4 main phyla of kingdom fungi

Answer 41

- chytridiomycota - zygomycota - basidiomycota - ascomycota

Question 42

myocoses

Answer 42

fungal infections in animals