10. Proteobacteria

Question 1

5 classes of proteobacteria? Which are anoxygenic photoautotrophs?

Answer 1

Alpha, beta, gamma, delta, epsilon

Anoxygenic photoautotrophs = alpha, beta, gamma

Question 2

All proteobacteria are gram-_______

Answer 2

negative

Question 3

Why are there no patterns of reproduction/norphology/metabolism among proteobacteria?

Answer 3

Because this is at the phylum level => too broad

Question 4

Ancestor of proteobacteria?

Answer 4

Purple photosynthetic bacteria

Question 5

Purple of purple bacteria are accessory “_________” pigments

Answer 5

carotenoid

Question 6

2 examples of alphaproteobacteria?

Answer 6

Rickettsia rickettsiae

Rhodobacter capsulatus

Question 7

Unique characteristic of Rickettsia rickettsiae = is an obligate ___________ _________

Answer 7

intracellular parasite (can only grow inside a host cell)

Question 8

When inside the host cell, what does R. rickettsiae control?
What disease does it cause?

Answer 8

Actin filament

Rocky mountain spotted fever

Question 9

R. rickettsiae is transmitted by..?

Answer 9

Ticks

Question 10

Rhodobacter capsulatus is a ____________ bacterium, but it can also be a ________ since it can fix nitrogen

Answer 10

photoorganotroph

heterotroph

Question 11

What bacteria is used in biotechnology for generating proteins?

Answer 11

Rhodobacter capsulatus

Question 12

2 examples of deltaproteobacteria?

Answer 12

Myxococcus xanthus

Bdellovibrio bacteriovorus

Question 13

How do Myxococcus xanthus and Bdellovibrio bacteriovorus kill bacteria?

Answer 13

M.xanthus - secrete antibiotics (can be grown in absence of prey)

B.bacteriovorus - Is a parasite that penetrates cell walls by secreting lytic enzymes

Question 14

Differences between amphi-, lopho-, mono-, and peri- trichous?

Answer 14

Amphitrichous - single flagellum at each end

Lophotrichous - cluster of flagella at one OR both ends

Monotrichous - single flagellum

Peritrichous - flagella distributed across its surface

Question 15

Short helical protein filaments that emanate from the organism are..?

Answer 15

Fimbriae/pilli

Question 16

2 functions of fimbriae?

Answer 16

Attachment to substratum

Mediate twitching motility (ATP-dependent)

Question 17

2 methods of flagella detection?

Answer 17

Indirectly - semi-solid agar

Directly - electron/light microscopy

Question 18

Structure of flagella?

Answer 18

Rigid helical filament made from the protein flagellin

Question 19

What is a flagellar hook?

Answer 19

“Universal joint” - links the flagellum to basal body

Question 20

How do flagellar filaments grow?

Answer 20

From the tip downward (not bottom up); the monomers then self-associate

Question 21

Movement of flagella is analogous to what?

Answer 21

Boat propeller

Question 22

Difference between what powers fimbria vs flagella?

Answer 22

Fimbria - ATP

Flagella - H+ gradient

Question 23

How fast can flagella rotate?

Answer 23

300-1000 rotations/sec

Question 24

2 types of purposeful movement? Difference?

Answer 24

Run - counter-clockwise rotation

Tumble - Clockwise rotation

Question 25

Change in flagellar motion = ________ + ____________

Answer 25

chemical + specific receptor

Question 26

What is chemotaxis?

Answer 26

A pattern of microbial behaviour in which the microbe moves toward/away from a chemical attractant

Question 27

Chemotaxis - what happens after an attractant binds to a specific plasma membrane receptor?

Answer 27

Series of phosphorylation rxns => change in flagellar motion

Question 28

3 differences between fimbria and flagella?

Answer 28

Flagella holow, fimbria solid Flagella uses H+ gradient, frimbria uses ATP Flagella uses whip-like motion, fimbria uses twitching

Question 29

Sensor kinase and response regulator in E.coli chemotaxis response?

Answer 29

``` CheA = sensor kinase CheY = response regulator ```

Question 30

Default rotation of E.coli flagellum?

Answer 30

CCW (run)

Question 31

Archaeal flagella resemble proteins in bacterial _______ more than bacterial __________

Answer 31

pili; flagellin

Question 32

Which is thinner, arachaeal or bacterial flagella?

Answer 32

Archaeal

Question 33

Which type of flagella are NOT hollow, bacterial or archaeal?

Answer 33

Archaeal

Question 34

Spirochete flagella associate to form _________ that twists around the bacterium

Answer 34

an axial fibril

Question 35

What is an MCP?

Answer 35

Methyl-accepting chemotaxis protein

Question 36

_____________ is a parasite of other G- bacteria

Answer 36

Bdellovibrio bacteriovorus

Question 37

Nutrients for Bdellovibrio bacteriovorus? Habitat?

Answer 37

NO carbs Uses pre-formed aa and purine/pyrmidine bases of the host Habitat = sewage, freshwater, soil