Extreme conditions

Question 1

What is optimum growth temperature?

Answer 1

the temperature at which the growth rate is the highest

Question 2

What is the maximum growth temperature?

Answer 2

highest temperature at which growth is possible

Question 3

what is the minimum growth temperature?

Answer 3

lowest temperature at which growth is possible

Question 4

What does it mean to be heat sensitive?

Answer 4

when the degree of tolerance to heat has a narrow range between minimum and maximum growth temperatures.

Question 5

classification of organism that has an optimum growth temperature between 28 and 38 degrees celcius?

Answer 5

Mesophiles

Question 6

classification of organism that has an optimum growth temperature below 16 degrees celcius?

Answer 6

Psychrophiles

Question 7

classification of organism that has an optimum growth temperature above 65 degrees celcius?

Answer 7

Thermophiles

Question 8

classification of organism that has an optimum growth temperature close to 100 degrees celcius?

Answer 8

hyperthermophiles

Question 9

Mesophilic temperature range?

Answer 9

20 - 45 degrees celcius

Question 10

thermophile temperature range?

Answer 10

45 to 80 degrees celcius

Question 11

psychrophile temperature range?

Answer 11

below 20 degrees celcius

Question 12

What optimum temperature does many pathogenic mesophiles have?

Answer 12

37 degrees celcius which is normal human temperature.

Question 13

True or false, psychrophilic spoilage bacteria do exist

Answer 13

True

Question 14

characteristic of the cytoplasm of a microbe

Answer 14

it contains a variety of dissolved materials, The concentrations of which are often higher than those obtained in their environments

Question 15

what is the selective permeable membrane?

Answer 15

it separates the intracellular and extracellular spaces.

it allows water to flow from a region of low solute concentration to a region of high solute concentration (osmosis)

Question 16

What creates osmotic pressure and what contributes to it?

Answer 16

a high solute concentration inside the cell creates the osmotic pressure. and the higher the intracellular solute concentration, the greater the osmotic pressure

Question 17

What causes an influx of water to a cell?

Answer 17

if the cell is placed in a medium of lower solute concentration

Question 18

What causes an efflux of water to a cell?

Answer 18

if a cell is placed in a medium of higher solute concentration.

Question 19

What is plasmoptysis?

Answer 19

the influx of water and the rapid increase in cell volume resulting in a rupture or explosion of the cell wall, leakage of cell material, and death of cell

Question 20

What is bacteriocidal?

Answer 20

when bacterial cell death occurs from plasmoptysis.

Question 21

What happens to the cell when there is efflux of water? what is this called?

Answer 21

1. cell will shrink
2. concentration of cellular contents will be reduced
3. disruption of the cell wall cell membrane interaction
4. decreased metabolic activity due to reduced intracellular water content.
   its called plasmolysis

Question 22

what is bacteriostatic?

Answer 22

prevention of growth of cell without killing it.

Question 23

what microbial strain is required to preserve food?

Answer 23

strains that are acid tolerant or acid loving