Lab 6

Question 1

What are Psychrophiles ?

Answer 1

Grow well at 0 degree Celsius; optimum: 15 degrees or lower

Question 2

What are Psychrotrophs?

Answer 2

Facultative psychrophiles; grow at 0 -7 Degrees Celsius

Question 3

What are Mesophiles ?

Answer 3

Growth optima 25-45 degrees Celsuis. Majority of bacterial species are in group 25-45 degrees Celsius

Question 4

What are Thermophiles?

Answer 4

grow at 55 degrees or higher

Question 5

What are Hyperthermophiles?

Answer 5

grow at 90 degrees or above (HIGHEST)

Question 6

What are Thermoduric?

Answer 6

bacteria that can survive boiling even though they cannot grow.
*Usually they are spore forming.

Question 7

ph range of Acidophiles

Answer 7

Thrive under highly acidic conditions (usually at ph 2.0) 0.0-5.5

Question 8

ph range of Neutrophiles

Answer 8

Thrive in neutral pH environment (6.5-7.5) 5.5-8.0. BACTERIA are mostly neutrophiles.

Question 9

ph range of Alkaliphiles

Answer 9

capable of survival in alkaline; growing optimally around a pH of 10 8.5-11.5

Question 10

Function of buffer when growing bacteria ?

Answer 10

To neutralize acids produced by bacteria and create a pH equilibrium.

Question 11

What is solute?

Answer 11

substance

Question 12

what is solvent?

Answer 12

liquid

Question 13

5 environmental factors that affect bacterial growth?

Answer 13

-temperature- specific growth temperature (determined by heat sensitivity of enzymes, membranes, ribosomes)
- pH- affects activity of enzymes. THOSE IN BIOSYNTHESIS
- osmotic pressure
- nature
- chemicals

Question 14

hypotonic:

Answer 14

BURST- water moves into the cell, low solute

Question 15

hypertonic

Answer 15

SHRINK- water leaves, high solute concentration. (plasmolysis)

Question 16

isotonic

Answer 16

SAME concentration of solute inside/outside cell membrane.

Question 17

what is a halophile?

Answer 17

tolerate saline(salt) concentrations