Intro to Bacteria II (lec 2)

Question 1

Flagella are?

purpose?

Answer 1

filament protein structure anchored to cell memb

motility (chemo-, photo-, aero- stimulated)

Question 2

Flagella are source of what antigen

Answer 2

H antigen

Question 3

Polar vs Peritrichous Flagella?

Answer 3

polar = on one or both ends

peritrichous = covers cell

Question 4

Fimbriae/Pili are?

purpose?

arranged?

Answer 4

hair-like protein structures

promote adherence
pili = conjugation

peritrichously

Question 5

Ribosomes structure?

Answer 5

bacteria = 70S (30S + 50S)

eukaryotes (fungi) = 80S (40S + 60S)

Question 6

What antibiotics target 70S?

Answer 6

aminoglycosides (genta-, streptomycin)

macrolides (azithro, erythro)

Question 7

Nucleoid (no membrane) contains?

allows for?

Answer 7

DNA, RNA, proteins

coupled transcription/translation (faster protein synth, faster response to environment)

Question 8

Endospores produced by what kind of bacteria?

Answer 8

G+

endospore = cell in dormant stage

Question 9

Endospores resist? (4)

Answer 9

desiccation
heat
disinfectants
acids

Question 10

Protective elements of endospores? (2)

Answer 10

keratin coat

internal dipicolinic acid

Question 11

What 2 G+ pathogens produce spores?

Answer 11

bacillus anthracis

clostridium tetani

Question 12

Binary Fission is?

Answer 12

asexual reproduction

cell splits into daughter cells

Question 13

4 phases of Growth Curve?

Answer 13

1) lag phase (metabolically active, not dividing)
2) LOG phase (rapid division at constant rate)
3) stationary phase (division rate = death rate, # of live cells constant)
4) death phase (no nutrient, high waste products)

Question 14

Optimal pH for:

acidophiles

neutrophiles

alkaliphiles

Answer 14

acidophiles = < 5.4

neutrophiles = 5.4 - 8.5

alkaliphiles = > 8.5

Question 15

Optimal temp for:

psychrophiles

mesophiles

thermophiles

Answer 15

psychrophiles = 15 -20 ºC

mesophiles = 25 - 40

thermophiles = 50 - 60

Question 16

Obligate means?

Answer 16

physically and biochemically limited to one environment

Question 17

Facultative means?

Answer 17

physically and biochemically adaptable to different environments

Question 18

Example to Obligate Aerobe?

Answer 18

m. tuberculosis

Question 19

Example of Obligate Anaerobe?

Answer 19

c. botulinum

Question 20

Enzymes necessary for Aerobes to convert ROS?

Answer 20

SOD (Δs superoxides to H2 and H2O2)

Peroxidase/Catalase (Δs H2O2 to H2O and O2)

Question 21

Facultative Anaerobes prefer?

Answer 21

aerobic metabolism

Question 22

Facultative Anaerobes use what for metabolism in anaerobic conditions?

Answer 22

fermentation

e.g. e. coli, bacillus

Question 23

2 types of pathogenic fermentation?

Answer 23

1) lactic acid (cavities)

2) H2 gas (gangrene)

Question 24

Microaerophiles O2 requirement?

Answer 24

best in low [O2],
many are capnophiles (CO2 lovers)

e.g. t. pallidum, s. pneumo, n. gonorr

Question 25

Aerotolerant Anaerobes O2 requirement?

Answer 25

survive in O2, don't use O2 for metabolism e.g. l. acidophilus

Question 26

What osmotic environment is lethal to bacteria?

Answer 26

hypertonic solutions

Question 27

Halophiles environments?

Answer 27

high salt e.g. (facultative) v. cholera, s. aureus

Question 28

Bacterial DNA characteristics?

Answer 28

dsDNA CCC (circle) Supercoiled

Question 29

Plasmid is?

Answer 29

extrachromosomal DNA not necess for survival code for resistance, toxins replicate autonomously

Question 30

Transformation is?

Answer 30

uptake of naked DNA from environment (product of lysed cell) DNA recombines w/ chromo DNA is receiving cell -> new gene expressed

Question 31

Conjugation is?

Answer 31

one-way, direct contact transfer of DNA: larger pieces Type IV system (slide 8) G+ thru pheromone G- thru pilus

Question 32

Transduction is?

Answer 32

chromosomal DNA transfer by bacteriophage (virus)

Question 33

Generalized Transduction uses what cycle?

Answer 33

Lytic Cycle: (slide 45) bacterial DNA packed into capsid = defective phage defective phase injects new bacteria w/ DNA

Question 34

Specialized Transduction uses what cycle?

Answer 34

Lysogenic Cycle: ``` phage injects viral DNA -> vDNA inserts into bacterial chromo (lysogeny) -> new DNA (prophage) make bacteria pathogenic ``` e.g. c. diptheriae, v. cholera

Question 35

What are Transponsons?

Answer 35

mobile genetic element, inserts into bacterial chromo/plasmid, responsible for most resistant genes

Question 36

Inclusion bodies are?

Answer 36

``` glycogen storage or structural blocks (sulfur, polyphosphates) ```