Ch 4

Question 1

essential nutrients definition

Answer 1

cannot be synthesized and must be supplied, otherwise growth ceases

Question 2

Required micronutrients

Answer 2

Co, Cu, Ni, Mn, Mo, Zn

Question 3

Required macronutrients

Answer 3

CHONPS
C:
Carbon
Proteins; nucleic acids
phospholipids
methionine \, cysteine

Question 4

autotrophs turn _____ into _____ while heterotrophs perform the reverse reaction

Answer 4

Carbon dioxide; complex organic carbon source

Question 5

C in CHONPS

Answer 5

carbon skeleton, form of carbon: CO2 or more complex

Question 6

N in CHONPS

Answer 6

Nitrogen;
proteins, nucleic acids
form: NH4, NO3, NO2

Question 7

P in CHONPS

Answer 7

Phosphorous
nucleic acids, phospholipids;
form: PO3

Question 8

S in CHONPS

Answer 8

sulfur
methionine, cysteine
form: SO4

Question 9

cations as required macronutrients

Answer 9

K+, Mg2+, Fe2+, Ca2+, serve as cofactors or signaling molecules

Question 10

growth factors

Answer 10

vitamins, amino acids, blood, serum, etc.

Question 11

nutrients ______ microbial growth

Answer 11

limit

Question 12

nutritional types

Answer 12

Prototroph: wild type
Auxotroph: deficient in a metabolic pathway; eg alanine auxotroph

Question 13

auto/hetero prefixes indicate _____ source

Answer 13

carbon;
CO2 or more complex

Question 14

photo/chemo prefixes indicate ______ source

Answer 14

energy;
light or non-light driven oxidations

Question 15

litho/organo indicate ______ source

Answer 15

electrons;
inorganic or organic

Question 16

macro and micro nutrients are combined to form a

Answer 16

growth medium

the sources of nutrients defines the type of medium

Question 17

complex media

Answer 17

possesses many pre-formed, nutrients that cells can readily assimilate

Question 18

from where are nutrients and growth factors provided in complex media

Answer 18

nutrients: primary protein source - beef, casein, soy protein, etc.
growth factors: yeast extract, beef extract

Question 19

defined media

Answer 19

chemical composition is known; cells must synthesize all required molecules

Question 20

what medium does a fastidious bacteria require

Answer 20

defined medium

Question 21

enrichment culture

Answer 21

provide conditions to enhance the growth of specific bacterial types; often these may be present at low numbers in an environmental sample

Question 22

selective media

Answer 22

contains chemical components that inhibit certain bacteria, favors the growth of others

Question 23

purpose of liquid medium

Answer 23

-growth studies
-biochemical analysis
-harvest cells for DNA
-protein isolation

Question 24

purpose of solid medium

Answer 24

-formation of colonies

Question 25

what purpose does agar serve in media

Answer 25

it solidifies a liquid medium into a solid

Question 26

differential media

Answer 26

can visualize metabolic differences between bacterial types

Question 27

bacteria grow in length & mass and divide via

Answer 27

binary fission

Question 28

at different times species can exhibit _______ growth rates

Answer 28

a continuum; from non-growth to rapid rates of increase

Question 29

generation time definition

Answer 29

length of time for a cell to divide; same as doubling time

Question 30

formula for population size (N)

Answer 30

Nt = No x 2^n n: # cells after n generations

Question 31

the rate of exponential growth is expressed as the

Answer 31

growth rate constant (k)

Question 32

stages of bacterial growth in batch culture

Answer 32

-lag -log -stationary -death

Question 33

what occurs during the lag phase

Answer 33

-no growth -acclimation to surroundings -turn on/off different genes -synthesis

Question 34

what factors affect lag phase

Answer 34

-inoculum age and size -media composition -physical factors

Question 35

what occurs during log phase

Answer 35

-rapid growth -most metabolically active state -cell size increases

Question 36

what marks late log phase?

Answer 36

slowing in growth of batch

Question 37

what occurs during stationary phase

Answer 37

-cell size decreases -stress response -nutrients limited -growth rate=death rate

Question 38

what occurs during death phase

Answer 38

-exponential decline in cell numbers -lack of nutrients/pH changes

Question 39

dormancy/persistence definition

Answer 39

growth arrested cells that remain viable; maintain membrane potential to provide energy

Question 40

fed-batch culture definition

Answer 40

batch is fed additional nutrients at mid-log phase; results in further growth

Question 41

where in controlled growth of a batch achieved?

Answer 41

in a bioreactor

Question 42

specialized surface-attached communities formed by bacteria are called

Answer 42

biofilms

Question 43

biofilm formation occurs in stages via ____

Answer 43

chemical/environmental signals

Question 44

initiation stage

Answer 44

planktonic cells (free swimming)

Question 45

attachment stage

Answer 45

fimbriae; "swimmers" -> "stickers"

Question 46

maturation stage

Answer 46

exopolysaccharide formation

Question 47

maintenance stage

Answer 47

2D -> 3D growth; biofilm towers

Question 48

dissolution stage

Answer 48

breakdown; triggered by starvation; sticker -> swimmer

Question 49

cellular communication / quorum sensing triggers

Answer 49

formation of exopolysaccharide from the microcolony forming an ECM of entrapped organic and inorganic molecules

Question 50

endospore formation is a response to

Answer 50

environmental stress

Question 51

what are the types of endospore formers

Answer 51

bacillus: aerobic clostridium: obligate anaerobes

Question 52

spores are highly resistant to

Answer 52

chemicals, heat, radiation; will germinate under favorable conditions

Question 53

sporulation is an

Answer 53

8 hour genetic program directing an asymmetrical division process forming a spore

Question 54

compartments formed during sporulation are

Answer 54

unequal: mother cell and forespore

Question 55

the coat formed during sporulation is

Answer 55

a thick spore coat containing peptidoglycan