CHAPTER 6

Question 1

what two groups of organisms based on source of carbon

Answer 1

autotrophs and heterotrophs

Question 2

what two groups of organisms based on source of energy

Answer 2

chemotrophs and phototrophs

Question 3

what two groups of organisms are based on source of electrons

Answer 3

organotrophs and lithotrophs

Question 4

what are organotrophs

Answer 4

heterotrophs, organic molecules are source of e-

Question 5

what are lithotrophs

Answer 5

autotrophs, inorganic molecules source of e-

Question 6

t or f

oxygen is essential for obligate aerobes

Answer 6

true

Question 7

t or f

oxygen is essential for obligate anaerobes

Answer 7

false; it is deadly

Question 8

what are 4 toxic forms of oxygen

Answer 8

singlet oxygen
superoxide radicals
peroxide anion
hydroxyl radical

Question 9

define obligate aerobe

Answer 9

cannot grow w/out oxygen

Question 10

define facultative anaerobe

Answer 10

prefer utilizing oxygen but can also can grow/survive w/out it

Question 11

define microaerophile

Answer 11

requires low amount of oxygen. high levels can be lethal

Question 12

define obligate anaerobe

Answer 12

lacks the enzymes to detoxify oxygen so cannot survive in an oxygen environment

Question 13

define aerotolerant anaerobes

Answer 13

do not utilize oxygen for metabolism but can survive and grow in its presence

Question 14

anabolism often ceases due to insufficient _______

Answer 14

nitrogen

Question 15

what happens in nitrogen fixation

Answer 15

convert atmospheric N2 to NH3 (essential to life on earth)

Question 16

define trace elements

Answer 16

elements required in small amounts

Question 17

define trace elements

Answer 17

elements required in small amounts

Question 18

define fastidious

Answer 18

organisms that need multiple growth factors

Question 19

what affects the 3D structure of proteins

Answer 19

temperature

Question 20

define cardinal temperatures

Answer 20

range of temperatures for microbial growth

Question 21

minimum vs maximum temperature

Answer 21

lowest/highest temp that permits a microbes growth and metabolism

Question 22

define optimum temperature

Answer 22

promotes the fastest rate of growth and metabolism

Question 23

define psychrophiles

Answer 23

optimum temp below 15 degrees C; capable of growth @ 0 degrees C

Question 24

mesophiles optimum temp

Answer 24

optimum temp 20-40 degrees C; most human pathogens

Question 25

psychrotroph optimum temp

Answer 25

grows below 20 degrees C

Question 26

thermophiles optimum temp

Answer 26

greater than 45 degrees C; generally range of 50-60 degrees C; found in hot springs

Question 27

Hyperthermophiles/ extreme thermophiles optimum temp

Answer 27

greater than 80 degrees C

Question 28

neutrophiles grow best in a narrow range around _____pH

Answer 28

neutral

Question 29

acidophiles grow best in

Answer 29

acidic habitats

Question 30

alkalinophiles live in

Answer 30

alkaline soils and water

Question 31

define hypotonic solutions

Answer 31

have lower solute concentrations; cell will swell in this solution

Question 32

define hypertonic solutions

Answer 32

have greater solute concentrations; cell will shrivel in this solution

Question 33

obligate halophiles thrive in

Answer 33

high salt environments

Question 34

barophiles live under extreme

Answer 34

pressure

Question 35

what is an antagonistic relationship

Answer 35

one of the members is harmed or killed

Question 36

what is a synergistic relationship

Answer 36

greater benefits together than alone

Question 37

what is symbiotic relationship

Answer 37

interdependent on eachother

Question 38

what is quorum sensing

Answer 38

the regulation of gene expression in response to fluctuations in cell population density

Question 39

define synthetic media

Answer 39

exact chemical composition is known

Question 40

define complex media

Answer 40

exact chemical composition is unknown

Question 41

define selective media

Answer 41

contain substances that favor or inhibit growth of particular microorgansims

Question 42

define differential media

Answer 42

allows growth of several types of microbes

Question 43

define anaerobic media

Answer 43

special culture conditions for obligate anaerobes

Question 44

define transport media

Answer 44

ensure clinical specimens are not contaminated

Question 45

Refrigeration stores for

Answer 45

short periods of time

Question 46

deep-freezing stores for

Answer 46

years

Question 47

lyophilization stores for

Answer 47

decades

Question 48

what is generation time

Answer 48

time required for a bacterial cell to grow and divide

Question 49

what is the lag phase of the growth curve

Answer 49

flat period of adjustment, enlargement, little growth

Question 50

what is the exponential growth phase of the growth curve

Answer 50

a period of maximum growth when cells have adequate nutrients

Question 51

what is the stationary phase of the growth curve

Answer 51

rate of cell growth = rate of cell death caused by depleted nutrients

Question 52

what is the death phase of the growth curve

Answer 52

as limiting factors intensify, cells due exponentially

Question 53

what is a chemostat

Answer 53

used to maintain a microbial population in a particular phase of growth

Question 54

coulter counter counts cells as they

Answer 54

interrupt an electrical current

Question 55

flow cytometry detects change in

Answer 55

light transmission as cells pass a detector

Question 56

what are the indirect methods of counting microbial reproduction

Answer 56

turbidity, metabolic activity, dry weight, genetic methods