Exam 3 Quiz 2

Question 1

Cocci Bianary fission

Answer 1

-dont have MreB
-caulobacter
-FtsZ ring
-Min C D E dont play a role
-active point of research

Question 2

when do antibiotics have an effect

Answer 2

the cell needs to be actively growing

Question 3

vasotracin

Answer 3

topical, inhibiting bactoprenol

Question 4

biofilm

Answer 4

-mushroom organization of bacteria
-antibiotics are not that effective on these

Question 5

caulobacter

Answer 5

MreB and CreS

Question 6

exponential growth

Answer 6

constant rate of growth, cell number doubles in regular time interval

Question 7

mathematics of growth

Answer 7

predict the number of bacteria cells that will arise during a growth period

Question 8

growth

Answer 8

fixed relationship between the initial number of bacteria and after a specific time period

Question 9

equation for growth

Answer 9

N_t=N₀2ⁿ

Question 10

N_t

Answer 10

population at time t

Question 11

N₀

Answer 11

initial population number

Question 12

n

Answer 12

number of generations in time t

Question 13

mean growth rate

Answer 13

log N_t - log N₀ / (0.031)(t)

Question 14

generation doubling time

Answer 14

1/k

Question 15

k

Answer 15

n / t

Question 16

batch culture

Answer 16

closed system, done in a test tube or flask

Question 17

batch culture growth curve

Answer 17

-lag phase
-exponential growth phase
-stationary phase
-death phasel

Question 18

lag phase

Answer 18

-shortest phase
-variable in time (30 mins - 5+ hrs)
- time depends on the size of the initial culture

Question 19

exponential growth phase

Answer 19

-nutrients there
-bacteria living at best/grow at their max
-cont last forever because the system is closed

Question 20

stationary phase

Answer 20

-equaling out bacteria growth
-see some decline bc of nutrient loss
-build-up of toxic wastes

Question 21

death phase

Answer 21

bacterial decline at exponential rate

Question 22

in the stationary phase we see

Answer 22

nutrient decline and persister cells show up, go into starvation mode and upregulate different proteins

Question 23

persister cells

Answer 23

live because of cryptic growth, grows off of their neighbors

Question 24

upregulation of proteins

Answer 24

-increase crosslinking in peptidoglycan
-increase chaperone protein to protect DNA
-bind enzymes to prevent denaturing

Question 25

viable but nonculturable state (VBNC)

Answer 25

-can come back with a lot of care -makes use of antibiotics important and difficult

Question 26

big disadvantage to viable counts

Answer 26

requires culturing and can only culture 1% of bacteria

Question 27

viable counts

Answer 27

way to get all the numbers used in the equations

Question 28

good colony count

Answer 28

30-300, if two viable to count , use the lower dilution (higher count)

Question 29

units for colony count

Answer 29

colony forming units per mL

Question 30

how to determine cfu/mL

Answer 30

plate count x DF x 1/amount plated

Question 31

DF

Answer 31

dilution factor

Question 32

hemocytometer

Answer 32

-easier to count -have individual bacteria counts -can count dead and alive cells -have higher count bc individual cells but mainly bc It COUNTS EVERYTHING -dilution still required -faster

Question 33

spectrophotometer

Answer 33

-turbidity -need to make a standard curve -only use preidentified -measures absorbance

Question 34

flow cytometer

Answer 34

hydrodynamic -needs a light source -can get forward and side scattered -gives more info

Question 35

foreward

Answer 35

gives cell size

Question 36

side scattered

Answer 36

gives cell granularity/ density inside cells

Question 37

continuous culture system

Answer 37

-chemostat -specific growth rate and cell density can be independently controlled

Question 38

what controls specific growth rate

Answer 38

dilution rate

Question 39

what controls density

Answer 39

concentration of a limiting nutrient

Question 40

dilution rate

Answer 40

rate at which new media is added and old media is taken out

Question 41

Temperature effects of microbial growth

Answer 41

bacteria cant thermoregulate, they are completely susceptible to their environement

Question 42

temperature range is defined by

Answer 42

three cardinal temperatures

Question 43

three cardinal temperatures

Answer 43

-minimum temperature -optimum temperature -maximum temperature

Question 44

what helps manage temperature

Answer 44

-enzymes (maximum end) -cell membrane (minimum end)

Question 45

optimum temperature

Answer 45

usually lies closer to maximum because thing happen faster in warmer environments (active sites)

Question 46

eukaryotic cutoff

Answer 46

65 C

Question 47

bacteria cutoff

Answer 47

95 C

Question 48

archaea temps

Answer 48

above 95C

Question 49

order of microbe classes by temperature

Answer 49

-psychrophile -mesophile -thermophile -hyperthermophile

Question 50

psychrophile

Answer 50

-15C or less -live in constantly cold environments (usually 1-5C) -oceans and frozen land

Question 51

psychrotolerants

Answer 51

-things that extend their ranges to grow in colder environments -ex. continue to grow when put in the fridge -listeria monocytogenes

Question 52

enzymes/proteins of psychrophiles

Answer 52

-more alpha helix -more polar, less hydrophobic interactions -cold shock/chaperone proteins

Question 53

membrane of psychrophiles

Answer 53

-unsaturated fatty acid with shorter chain -more cryoprotectants -extra coating called exopolysaccharide layer

Question 54

cryoprotectants

Answer 54

-offset freezing point inside a cell -have glycerol and sugars

Question 55

exopolysaccharide layer

Answer 55

-extra layer of insulation -sticky, commonly seen in biofilms