Lab 8

Question 1

What are classifications of some temperatures

Answer 1

psychrophiles
mesophiles
thermophiles

Question 2

What are classifications of some pH

Answer 2

acidophiles
Neutrophiles
alkaphieles

Question 3

What are classifications of osmolality

Answer 3

osmotolerant
non-osmotolerant

Question 4

What are a species cardinal temperatures

Answer 4

minum, maxium, ptimume

Question 5

What are pshychrophiles

Answer 5

only grow below 20 degrees

Question 6

What are mesophiles

Answer 6

grow betwen 15 to 45 - most pathogens

Question 7

What are thermophiles

Answer 7

grow above 40

Question 8

what are hyperthermolphiesl

Answer 8

above 80

Question 9

E. coli

Answer 9

E. coli is a mesophile that grows best at 37 degrees Celsius in neutral pH environments

Question 10

Thermophile

Answer 10

Bacillus stearothermophilus

Question 11

Bacillus stearothermophilus

Answer 11

Bacillus stearothermophilus is a thermophilic, optimal temperature range (center, 65 degrees C), 39ºF (4ºC) to 118ºF (48ºC).

Question 12

example of psychophile

Answer 12

Micrococcus cryophilus

Question 13

Bacillus subtilis,

Answer 13

mesophilic bacteria

Question 14

What does low temperatures do to mriobes

Answer 14

membranes can solidify and enzymes do not function properly

Question 15

What do very hgih temepratures do

Answer 15

Damanged is caused by denaturing enzymes and other proteins and disrupt the microbial memrbane

Question 16

How does extreme pH affect microorganisms

Answer 16

Affects the structure of all macromolecules including the hydrogen bondin holding together DNA and lipid molecules and protien

Question 17

What is the compoennt of the cell thats most sensitvie to PH

Answer 17

Protein. moderate changes and modify amino acid functional groups and disrupt hydrogen bonding -> affect protein folding and promote denaturation

Question 18

Which organisms are neutrophiles

Answer 18

E. coli
Staphylococcus
Salmonella

Question 19

Give 2 acidophiles

Answer 19

Saccharomyces cerevisiae (4-6)

Lactobacillus casei

Question 20

Use of high concentrations of salt and sugar

Answer 20

increase osmotic pressure -> create hypertonic enviornment that doesnt support the growth of microorganisms

Question 21

Why do prokaryoties need water

Answer 21

To maintiain cellular turgor pressure and to avoid plasmolysis which is the shrinkage of the cell memrbane as water leaves the cell

Question 22

what are some osmotolerant speices

Answer 22

Staphylococcus spp.

Question 23

What are non-osmotolerant species

Answer 23

cannot survive less than 3%

Question 24

What are halophiles

Answer 24

require > 3% to surve

Question 25

what are extreme haophiles

Answer 25

require > 25% to ssruvive

Question 26

Halophilic bacteira

Answer 26

Saccharomyces cerevisiae Staphylococcus epidermidis

Question 27

What is thermal death time

Answer 27

the time needed to kill a specific number of microorganisms at a specific temeprature

Question 28

What is the decimal reduction value (D value)

Answer 28

The time in minutes required to reduce the number of viable cells in a population by one logarithmic cycle of 90%. Independent of magnitude of the popuatiom