BMSC210 CH4.3

Question 1

What phylum do the majority of gram-negative bacteria belong to?

Answer 1

Proteobacteria

Question 2

What are gram-negative bacteria that do not belong to the phylum Proteobacteria called?

Answer 2

Nonproteobacteria

Question 3

What are three classes of gram-negative nonproteobacteria?

Answer 3

Spirochetes, CFB group, Planctomycetes

Question 4

How are spirochetes characterized?

Answer 4

Long, spiral-shaped bodies

Question 5

Why is it difficult to examine spirochetes under a conventional brightfield microscope?

Answer 5

They are very thin

Question 6

What type of microscopy is typically used to examine spirochetes?

Answer 6

Darkfield fluorescent microscopy

Question 7

Why are spirochetes difficult or impossible to culture?

Answer 7

They are highly motile

Question 8

What is the axial filament of a spirochete?

Answer 8

Similar to a flagellum, but wraps around the cell and runs inside the cell body of a spirochete in the periplasmic space between the outer membrane and the plasma membrane.

Question 9

Are there spirochetes that are human pathogens?

Answer 9

Yes

Question 10

What are the gram-negative nonproteobacteria of the CFB group called?

Answer 10

Cytophaga, Fusobacterium, and Bacteroides

Question 11

What are fusobacteria?

Answer 11

Bacteria that inhabit the human mouth - They may cause severe infectious diseases.

Question 12

What type of environments are CFB bacteria adapted to?

Answer 12

Anaerobic environments

Question 13

What is the main function of CFB bacteria in ruminant animals?

Answer 13

To process cellulose in the rumen

Question 14

What are Cytophaga?

Answer 14

Motile aquatic bacteria that glide.

Question 15

Which is the largest genus of the CFB group?

Answer 15

Bacteroides

Question 16

Where are Bacteroides commonly found?

Answer 16

Human large intestine

Question 17

What percentage do Bacteroides make up in the entire gut microbiome?

Answer 17

About 30%

Question 18

What do bacteria like Bacteroides benefit from in the gut?

Answer 18

Nutrients in the gut

Question 19

How do humans benefit from Bacteroides in the gut?

Answer 19

Prevention of pathogen colonization

Question 20

What happens to the gut when populations of Bacteroides are reduced?

Answer 20

Increased susceptibility to pathogenic bacteria and fungi

Question 21

Which species of Bacteroides is pathogenic?

Answer 21

B. melaninogenicus

Question 22

Where are Planctomycetes found?

Answer 22

Aquatic environments

Question 23

How do Planctomycetes reproduce?

Answer 23

By budding

Question 24

What are swarmer cells?

Answer 24

Motile cells not attached to a surface

Question 25

What allows sessile cells to attach to surfaces in the water?

Answer 25

a holdfast

Question 26

What is the primary source of energy for phototrophic bacteria?

Answer 26

Sunlight

Question 27

How do phototrophic bacteria synthesize ATP?

Answer 27

They use solar energy through photosynthesis.

Question 28

What is the difference between oxygenic and anoxygenic photosynthesis?

Answer 28

Oxygenic photosynthesis produces oxygen, while anoxygenic photosynthesis does not.

Question 29

Which type of photosynthesis do the majority of phototrophic bacteria perform?

Answer 29

Anoxygenic photosynthesis.

Question 30

What pigments do purple or green bacteria use for photosynthesis?

Answer 30

Bacteriochlorophylls.

Question 31

What are some of the accessory pigments found in bacteria?

Answer 31

Carotenoids

Question 32

What colors can the bacteria with carotenoids appear?

Answer 32

Orange, red, purple, green

Question 33

How are bacteria with carotenoids classified?

Answer 33

Sulphur and nonsulphur

Question 34

What type of photosynthesis do sulphur bacteria perform?

Answer 34

Anoxygenic photosynthesis

Question 35

What do sulphur bacteria use as electron donors?

Answer 35

Sulphites

Question 36

What is released by sulphur bacteria during photosynthesis?

Answer 36

Free elemental sulphur

Question 37

What pigments give purple sulphur bacteria their purple color?

Answer 37

Bacteriochlorophylls and carotenoids

Question 38

What is the genus of bacteria that are purple?

Answer 38

Chromatium

Question 39

Where do sulphur Gammaproteobacteria live?

Answer 39

Water

Question 40

What is the only source of carbon for sulphur Gammaproteobacteria?

Answer 40

Carbon dioxide

Question 41

What greenhouse gas is produced by Chlorobium?

Answer 41

Methane

Question 42

What is the implication of Chlorobium in climate change?

Answer 42

It produces methane, a greenhouse gas

Question 43

What are the special vesicle-like organelles called where bacteriochlorophyll is stored?

Answer 43

Chlorosomes

Question 44

What is the potential value of green nonsulphur bacteria in the field of biotechnology?

Answer 44

Ability to produce biological plastic and hydrogen fuel

Question 45

How are green nonsulphur bacteria different from green sulphur bacteria?

Answer 45

Use substrates other than sulphides for oxidation

Question 46

What is the proposed role of cyanobacteria in the Earth's atmosphere change?

Answer 46

Change from anoxic to oxygen-rich environment

Question 47

Where can cyanobacteria thrive?

Answer 47

Many habitats, including marine and freshwater environments, soil, and even rocks

Question 48

What range of temperatures can cyanobacteria tolerate?

Answer 48

Wide range, even extreme temperatures of the Antarctic

Question 49

How do cyanobacteria live?

Answer 49

Unicellular or in colonies, filamentous, forming sheaths or biofilms

Question 50

What is a notable ability of many cyanobacteria?

Answer 50

Nitrogen fixation

Question 51

What is the primary photosynthetic pigment in Cyanobacteria?

Answer 51

Chlorophyll a

Question 52

What process gave rise to the eukaryotic chloroplast?

Answer 52

Endosymbiosis with an ancestor of cyanobacteria