unit 2 chapter 4

Question 1

elements required for growth (6)

Answer 1

carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur (CHNOPS)

Question 2

trace elements involved in growth (5)

Answer 2

iron, colbalt, nickel, magnesium, manganese

Question 3

grows only when oxygen is available; requires oxygen for respiration

Answer 3

obligate aerobe

Question 4

grows best w/ oxygen present, but can grow without oxygen as well

Answer 4

facultative anaerobe

Question 5

cannot grow at all when oxygen is present

Answer 5

obligate anaerobe

Question 6

requires oxygen for respiration, but only grows w/ small amounts of oxygen

Answer 6

microaerophile

Question 7

can grow well with or without oxygen

Answer 7

aerotolerant anaerobe

Question 8

nitrogen fixation

Answer 8

gas to solid/liquid

Question 9

nitrogen fixation by ____ is essential to life on Earth

Answer 9

bacteria

Question 10

order of nitrogen cycle in terms of bacteria

Answer 10

1. nitrogen fixing bacteria
2. nitrifying bacteria
3. denitrifying bacteria

Question 11

bacteria genus for nitrogen fixing

Answer 11

rhizobium

Question 12

what enzyme does rhizobium use to turn nitrogen to ammonia?

Answer 12

nitrogenase

Question 13

what does the first step of the nitrogen cycle (nitrogen fixing; rhizobium) do?

Answer 13

turn nitrogen into ammonia using nitrogenase as an enzyme (N2 => NH3)

Question 14

bacteria genus used for nitrifying bacteria (2)

Answer 14

nitrosomonas and nitrobacter

Question 15

photo-

Answer 15

light

Question 16

chemo-

Answer 16

chemical

Question 17

-auto

Answer 17

carbon dioxide

Question 18

-hetero

Answer 18

organic

Question 19

monomers of protein polymers

Answer 19

amino acids

Question 20

used by mycoplasmas for cell membranes

Answer 20

cholesterol

Question 21

functional portion of cytochromes in electron transport system

Answer 21

heme

Question 22

electron carrier

Answer 22

NADH

Question 23

precursor of folic acid

Answer 23

PABA (para-aminobenzoic acid)

Question 24

precursor of NAD+

Answer 24

niacin (vitamin B3)

Question 25

example of photoautotroph

Answer 25

plants, algae (O2 is byproduct)
green/purple sulfur bacteria (no O2 produced)

Question 26

example of chemoautotroph

Answer 26

humans

Question 27

why are humans considered chemoautotrophs?

Answer 27

chemo - humans consume food/liquids, which are broken down into chemicals
automatically - we breathe out CO2 as a byproduct

Question 28

main trace element

Answer 28

Fe2+ of Fe3+

Question 29

superoxide dismutase (SOD)

Answer 29

enzyme that converts superoxide radicals into hydrogen peroxide

Question 30

catalase

Answer 30

enzyme that turns hydrogen peroxide to H2O and O2

Question 31

denitrifying bacteria

Answer 31

nitrate turns into nitrogen again (NO3 => N2)

Question 32

what does nitrosomonas do? (1st part of nitrifying bacteria)

Answer 32

turns ammonia into nitrite (NH3 => NO2)

Question 33

what does nitrobacter do? (2nd part of nitrifying bacteria)

Answer 33

turns nitrite into nitrate (NO2 => NO3)

Question 34

what do plants use as food out of the nitrogen cycle?

Answer 34

nitrate (NO3)

Question 35

complex communities of microorganisms living symbiotically on surfaces

Answer 35

biofilms

Question 36

what are biofilms incapable of doing with the exception of in a lab?

Answer 36

being grown in pure culture

Question 37

neutralism

Answer 37

a form of biofilm communities in which both parties benefit

Question 38

commensalism

Answer 38

a form of biofilm communities in which one party benefits and the other one doesn’t