Microbial Growth

Question 1

Obligate Aerobes

Answer 1

oxygen required for growth (aerobic)

Question 2

Facultative Anaerobes

Answer 2

aerobic and anaerobic, greatest growth in presence of oxygen

Question 3

Obligate Anaerobes

Answer 3

only anaerobic growth (no oxygen), ceases in presence of oxygen

Question 4

Aerotolerant Anaerobes

Answer 4

only anaerobic growth (no oxygen), but continues in presence of oxygen, ‘tolerant’

Question 5

Microaerophiles

Answer 5

only aerobic growth, oxygen required in low concentrations

Question 6

Growth occurs where high concentrations of oxygen have diffused into the medium

Answer 6

Obligate Aerobes

Question 7

Growth occurs evenly, oxygen has no effect

Answer 7

Aerotolerant Anaerobes

Question 8

Growth occurs only where there is no oxygen

Answer 8

Obligate Anaerobes

Question 9

Growth is best where most oxygen is present, but occurs throughout the tube

Answer 9

Facultative Anaerobes

Question 10

Growth is best only where a low concentration of oxygen has diffused into medium

Answer 10

Microaerophiles

Question 11

superoxide dismutase (SOD)

Answer 11

allows organism to neutralize and produces hydrogen peroxide, enzyme used to neutralize free radicals (o2-)

Question 12

Singlet Oxygen

Answer 12

higher energy state, extremely reactive, ingest bacteria

Question 13

Superoxide Free Radicals (o2-)

Answer 13

instable, toxic to cellular components, formed during normal respiration, convert free radicals into molecular O2

Question 14

O2 -2 (Peroxide Ion in Hydrogen Peroxide)

Answer 14

aerobic respiration produced Catalase, when pour hydrogen on skin, Catalase neutralizes hydrogen peroxide

Question 15

Hydroxyl Radical (OH)

Answer 15

intermediate form of oxygen, most reactive, formed in cellular cytoplasm

Question 16

Obliate Anaerobes DONT produce

Answer 16

Superoxide dismutase, Catalase

Question 17

Complex Media

Answer 17

culture medium in which the exact composition is not known, varies from batch to match

Question 18

Chemical Defined Media

Answer 18

exact chemical composition is known, used for laboratory and autotrophic bacteria

Question 19

Binary Fision

Answer 19

Division

Question 20

Budding

Answer 20

forms outgrowth/bud which stay attached until reaches size of parent cell, then detaches

Question 21

Filamentous Bacteria Reproduction

Answer 21

simply fragment, these fragment initiate growth of new cell

Question 22

Pure Culture

Answer 22

Spread out colony of bacteria (streak plate method [most common]), visible mass of microbial cells arising from one cell or from group of the same microbe

Question 23

Chemically Defined Media

Answer 23

exact chemical composition know

growth of chemoautrophs, photoautotrophs

Question 24

Complex Media

Answer 24

exact chemical composition is unknown

Question 25

Reducing Media

Answer 25

growth of obligate anaerobes

Question 26

Differential Media

Answer 26

differentiation of colonies of desired microbes from others

Question 27

Enrichment Media

Answer 27

designed to increase number of desired microbes to detectable level

Question 28

Selective Media

Answer 28

Supression of unwanted microbes, encouraging desired microbes

Question 29

Generation Time

Answer 29

time required for cell to divide, only consider for binary fission

Question 30

E.Coli can reproduce every

Answer 30

20 minutes

Question 31

Most bacteria have a generation time of

Answer 31

1-3 hours, very rapidly