Bacterial Growth and Nutrition

Question 1

T/F: Growth is the increase in size when a cell takes up water, lipids or polysaccharide deposits

Answer 1

False

Question 2

Composes 50% of the phospholipid bilayer of the cell membrane

Answer 2

Carbon

Question 3

Carbon obtained from breakdown of pre-existing molecules to produce new substances

Answer 3

Chemoheterotrophs

Question 4

Carbon obtained from carbon dioxide molecules

Answer 4

Chemoautotrophs

Question 5

Contributes to heat resistance for gram (+) bacteria and endospore formation

Answer 5

Calcium

Question 6

Acts as cofactor for enzymes and also component ofmcytochromes

Answer 6

Iron

Question 7

Uptake of iron by bacteria is facilitated by? It acts to chelate iron and promote its transport

Answer 7

Siderophore

Question 8

Stabilizes ribosomes and cell membrane

Answer 8

Magnesium

Question 9

Essential for membrane integrity

Answer 9

Potassium

Question 10

Bacteria found in arctic and deep sea environments

Answer 10

Psychrophiles

Question 11

Involved in low temp food spoilage

Answer 11

Psychrotrophs

Question 12

Microorganisms that require salt for growth

Answer 12

Halophiles

Question 13

Marine bacteria

Answer 13

Halophiles

Question 14

Common cause of seafood poisoning

Answer 14

Vibrio parahemolyticus (halophile)

Question 15

Favor hypertonic environments

Answer 15

Osmophiles

Question 16

Persists in dry environments

Answer 16

Xerophiles

Question 17

Normal animal flora found in stool

Answer 17

Clostridium tetani

Question 18

Can grow in 21% oxygen

Answer 18

Mycobacteria, Legionella (aerobes)

Question 19

Require CO2 for growth (aerobe)

Answer 19

N. gonorrhea

Question 20

Do not require oxygen for growth but uses it for ATP

Answer 20

Facultative anaerobes

Question 21

Highly susceptible to superoxide radical formation

Answer 21

Anaerobes

Question 22

Creates acidic environment in vagina

Answer 22

Lactobacillus acidophilus

Question 23

Barophiles die in low hydrostatic pressure environments because of?

Answer 23

Gas vesicle formation

Question 24

Mannitol salt agar is an example of which type of artificial media

Answer 24

Selective

Question 25

Example of differential type of artificial media

Answer 25

MacConkey agar, EMB agar

Question 26

Type of artificial media usually used for testing water quality

Answer 26

Selective-Differential

Question 27

T/F: Enrichment type of artificial media increases the growth of a particular species without affecting the growth of others

Answer 27

True

Question 28

T/F: Growth is usually rapid at the center of the colony and slowest at the edge

Answer 28

False

Question 29

T/F: The greater the size of the inoculum, the longer the lag phase

Answer 29

True

Question 30

T/F: Cells are not in the steady state during the log phase

Answer 30

False

Question 31

During stationary phase, growth has already ceased because of (3)

Answer 31

Exhausted nutrients
Loss of “biological space”
Accumulation of toxic end products

Question 32

T/F: Viable cell count stays constant during stationary phase

Answer 32

True

Question 33

Uses counting chamber for cell count

Answer 33

Direct counting

Question 34

T/F: Direct counting distinguishes between alive and dead cells

Answer 34

False

Question 35

Useful for measuring fungal growth

Answer 35

Direct counting

Question 36

Measured through light absorption

Answer 36

Turbidity

Question 37

Done to ensure continuous cell growth

Answer 37

Open culture

Question 38

Open culture that is more effective at higher dilution rates

Answer 38

Turbidostats