Lecture 17

Question 1

Archaea

Answer 1

features in common with eukarya (rep, transcrip and transla), common with bacteria (size, no nucleus)
Highly diverese

Question 2

Archaeal shape

Answer 2

cocci, rods common, 1-2 x 1-5 um for rods, 1-3 um in diameter for cocci

Question 3

Archaeal cell morphology

Answer 3

coccus, branched, filamentous

Question 4

archaeal cell walls

Answer 4

lack peptidoglycan, protein sheath

Question 5

Archaeal membrane

Answer 5

unique lipids: isoprene units, ether linkages (rather than ester to glycerol)

Question 6

Archaeal lipids

Answer 6

branched chain hydrocarbons attached to glycerol by ether linkages

Question 7

Differences of archaeal flagella

Answer 7

powered by ATP (rather than H+), filament is hollow, hook and basal body hard to distinguish, growth occurs at base not end

Question 8

Dna replication in Archaea

Answer 8

hybrid, single origin of replication, use same DNA polymerases as euks,

Question 9

Transcription in archaea

Answer 9

occurs in cytoplasm, mRNA might be polycistronic, introns rare, use 1 RNA polymerase

Question 10

Transcription in euks

Answer 10

nucleus, RNA moves to cytoplasm, genes split or interrupted, have exons

Question 11

Transcription in euks (promotors)

Answer 11

RNA polymerase 2 must be recruited to a promotor, several elements define core promotor, euk and archaeal share sequences

Question 12

Transcription factors (euk)

Answer 12

Rna polymerase 2 must be properly aligned on promotor, euks and archaea use transcription factors (they bind to DNA and recruit RNA polymerase)

Question 13

Biogeochemical cycling

Answer 13

oxidation + reduction of substances carried out by living organisms/ abiotic processes, cycling pf elements in diff parts of ecosystem

Question 14

Carbon cycle

Answer 14

carbon fixation - conversion of co2 into organic matter by microbes and plants, carbon enters common pool of organic matter that can be oxidized back into Co2

Question 15

Methanogens

Answer 15

archaea that produce methane, largest group of cultured archaea, 16s rRNA

Question 16

Methanogenesis

Answer 16

final step in decay of organic matter - generates CH4 (anaerobic environments), terminal electron acceptor is carbon

Question 17

Reduction to methane

Answer 17

inorganic carbon can reduce anaerobically to methane, methane diffuses upward and is oxidized by other microbes

Question 18

Importance of methanogens

Answer 18

wastewater treatment, produce significant amounts of methane (1 billion tons), clean burning fuel

Question 19

microbial containment candidates

Answer 19

potential pathogens that can survive in water and represent serve health risks

Question 20

Adenoviruses (waterborne)

Answer 20

resp illness sometimes GI diseases

Question 21

Caliciviruses

Answer 21

cause self limiting nausea, vomiting, diarrhea

Question 22

campylobacter jejuni

Answer 22

nausea, vomiting, diarrhea

Question 23

Entero virus

Answer 23

polio, can cause CNS disorders

Question 24

E.coli O157:H7

Answer 24

serve GI illness

Question 25

helicobacter pylori

Answer 25

bacterium can cause gastic ulcers and cancer

Question 26

Hep A

Answer 26

liver disease/ jaundice

Question 27

Legionella pneumophila

Answer 27

hot water system, bacterial pneumonia when inhaled

Question 28

mycobacterium avium

Answer 28

resp illness (w/ immunosuppresion)

Question 29

Naegleria fowleri

Answer 29

protazoan found in warm surfaces and ground water (meningoencephalitis)

Question 30

Salmonella enterica

Answer 30

GI illness

Question 31

Shigella sonnei

Answer 31

GI illness, bloody diarrhea

Question 32

Water purification

Answer 32

coagulation: chemical cogulats like alum and lime added flocs: coagulated particles rapid sand filters: physically traps particles water disinfected: chlorine, ozone, UV

Question 33

Indicator organisms

Answer 33

coliforms: gram -, ferment lactose, environment in feces of warm blooded animals, presence indicates fecal organisms may be present

Question 34

Tests to detect coliforms

Answer 34

colilert defined substrate test Membrane filter technique Multiple tube fermentation test

Question 35

Multiple tube fermentation test

Answer 35

1. water sample added to lactose or lauryl tryptose broth - gas indicates co2 formation 2. pos sample inoculated into green lactose broth 3. Pos tubes inoculated into Eosin methylene blue plates (inhibits gram +) 4. gram staining, microscopy