Chapter 6

Question 1

Heterotrophs

Answer 1

organism that must obtain its CARBON in an organic form (plants or animals)

Question 2

Autotrophs

Answer 2

organism that uses inorganic CO2 as its CARBON source (self-feeder)
- not nutritionally dependent on other living things

Question 3

Phototrophs

Answer 3

microbes that photosynthesize and gain ENERGY from sunlight

Question 4

Chemotrophs

Answer 4

microbes that get their energy from chemical compounds

Question 5

2 types of chemoautotrophs

Answer 5

1) Chemoorganic autotrophs = energy source from organic compounds, carbon source from inorganic compounds
2) Chemolithoautotrophs = energy source from inorganic compounds (minerals); require neither sunlight nor organic nutrients

Question 6

3 types of chemoheterotrophs

Answer 6

1) chemoheterotroph = metabolic conversion of the nutrients from other organisms
2) Saprobe = metabolizing the organic matter of dead organisms (decomposer)
3) Parasite = utilizing the tissues, fluids of a live host

Question 7

psychrophiles

Answer 7

optimum temperature below 15 degrees, cannot grow above 20 degrees

Question 8

psychrotrophs

Answer 8

optimum temp between 15 and 30 degrees; grow slowly in the cold

Question 9

mesophiles

Answer 9

grow between 20 and 40 degrees; majority of medically significant microorganisms

Question 10

thermoduric microbes

Answer 10

can survive short exposure to high temps but are normally mesophiles

Question 11

thermophiles

Answer 11

grow optimally at temps > 45 degrees

Question 12

extreme thermophiles

Answer 12

grow between 80 and 121 degrees

Question 13

aerobes

Answer 13

use gaseous oxygen in their metabolism, and can process toxic oxygen products

Question 14

obligate aerobe

Answer 14

cannot grow without oxygen

Question 15

microaerophiles

Answer 15

harmed by normal atmospheric concentrations of oxygen, but require a small amount of it in metabolism

Question 16

facultative anaerobe

Answer 16

do not require oxygen for metabolism, but use it when present

Question 17

anaerobes

Answer 17

lake the metabolic enzymes for using oxygen in respiration

Question 18

obligate anaerobes

Answer 18

lack enzymes for processing toxic oxygen and die in its presence

Question 19

aerotolerant anaerobes

Answer 19

do not utilize oxygen but can survive and grow to a limited extent in its presence

Question 20

capnophiles

Answer 20

organisms that grow best at higher CO2 tension than is normally present in the atmosphere

Question 21

acidophiles

Answer 21

organisms that thrive in acidic environments

Question 22

alkalinophiles

Answer 22

organisms that thrive in alkaline conditions

Question 23

osmophiles

Answer 23

live in habitats with high solute concentration

Question 24

halophiles

Answer 24

prefer high salt concentrations

Question 25

facultative halophiles

Answer 25

remarkably resistant to salt, although do not normally ride in high salt conditions

Question 26

barophiles

Answer 26

exist under pressures that range from a few times to over 1000 times the pressure of the atmosphere

Question 27

mutualism

Answer 27

organisms live in an obligatory but mutually beneficial relationship

Question 28

commensalisms

Answer 28

commensal receive benefits while its partner is neither harmed nor benefited

Question 29

parasitism

Answer 29

host organism provides the parasitic microbe with nutrients and a habitat host suffers from the relationship