Cultivation, Reproduction And Growth Of Bacteria Flashcards Preview

Microbiology 210 > Cultivation, Reproduction And Growth Of Bacteria > Flashcards

Flashcards in Cultivation, Reproduction And Growth Of Bacteria Deck (66)
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1

Growth of bacteria is represented by

Increase in number of cells rather than size

2

Requirements for growth

Nutritional and physical

3

Nutritional Requirements for growth

Energy and carbon source
Nitrogen
Sulfur
Phosphorus
Potassium magnesium and calcium
Trace elements
Organic growth factors
Water

4

Phototrophs and chemotrophs

Use solar energy as source of energy

Oxidize chemical compounds for energy

5

All organisms require a ____ source as it is the structural basis of biochemicals

Carbon

6

Heterotrophs and autotrophs

Use an organic carbon source

Use CO2 as a carbon source

7

Four nutritional classes of microorganisms

Chemoautotrophs (chemolithoautotrophs)

Chemoheterotrophs

Photoautotrophs

Phtoheterotrophs

8

Nitrogen is needed for_____
Obtained:

Protein and nucleic acid synthesis

Obtained via decomposition of proteins or from NH4+ or NO3-

Some bacteria can fix nitrogen

9

Sulfa is needed to

Sources

Synthesize sulfur contained amino acids and vitamins (thiamine and biotin)

Sources: sulfate ions, hydrogen sulfide, amino acids

10

Phosphorous is needed

Source

For synthesis of nucleic acids, phospholipids and ATP

Phosphate ions

11

Potassium, Magnesium and calcium function as

Cofactors for enzymes

12

Trace elements

Required in small amounts and essential for enzyme activity and act as cofactors usually.

13

Organic Growth Factors (definition)

Organic compounds essential for the growth of bacterium that cannot be manufactured by the bacterium; must be obtained from the environment

14

Organic growth factors

Vitamins - (coenzymes) either manufactured or obtained via environment

Amino Acids - needed for protein synthesis

Purines and pyrimidines - needed for nuclei acid synthesis

15

Water

Nutrients must be in solution with water to be used

16

Physical conditions required for growth

Temperature
Gaseous atmosphere
pH (Acidity or alkalinity)
Other (osmotic pressure, salinity, light, hydrostatic pressure)

17

Temperature as a condition for growth

Affects growth, reaction rates and amount of growth. Most bacteria grow within a limited range of temperature

18

Classification of organisms based on temperature

Psychorphiles
Mesophiles
Thermophiles

19

Psychrophiles

Cold loving

20

Mesophiles

Moderate temperature loving microbes

21

Thermophiles

Heat loving

22

Optimum growth temperature

Temp in which organism grows most rapidly

23

Psychotrophs

(Insert

24

Hyperthermophiles

Insert

25

Obligate aerobes

Use molecular oxygen and produce more energy from nutrients than do microbes that do not use oxygen

26

Facultative anaerobes

Use molecular oxygen when present but are able to use fermentation or anaerobic respiration when free oxygen is not available

27

Obligate Anaerobes

Cannot use molecular oxygen for energy yielding reactions

28

Aerotolerant anaerobes

Cannot use oxygen for growth, but tolerate it

29

Microaerophiles

Grow only in oxygen concentrations lower than air

30

What must AEROBES, FACULTIVE ANAEROBES & AEROTOLREANT ANAEROBES have to neutralize superoxide free radicals formed in the presence of atmospheric oxygen?

Enzyme: superoxide dismutase and either catalase or peroxidase