Microbial Growth and Nutrition- PT 1 Test 1

Question 1

supply of elements required by cells for growth

Answer 1

nutrients

Question 2

nutrients required in large amounts

Answer 2

macronutrients

Question 3

nutrients required in small amounts trace metals and growth factors

Answer 3

micronutrients

Question 4

What six elements does every organism need?

Answer 4

water, carbon, oxygen, hydrogen, nitrogen, phosphorous, sulfur

Question 5

What are the major macro molecules in the cell?

Answer 5

carbs, proteins, lipids, nucleic acids

Question 6

-must contain all the nutrients required by the organism for growth
-classification of physical nature, chemical constituents from which they are made, function

Answer 6

culture media

Question 7

exact chemical composition known

Answer 7

defined media

Question 8

composed of digests of microbial animal or plant products

Answer 8

complex media

Question 9

contains compounds that selectively inhibit growth of some microbes but not others

Answer 9

selective medium

Question 10

contains an indicator, usually a dye, that detects specific metabolic reactions during growth

Answer 10

differential medium

Question 11

What are the solidifying agents commonly used?

Answer 11

-gelatin, starch, agar

Question 12

-complex polysaccharide isolated from red algae
-solid at room temp liquefies at boiling cools and solidifies at 42 degrees Celsius
-provides framework
-not digestible for most microbes

Answer 12

agar

Question 13

-microscopic cell count- observing and enumerating cells present
-dried on slides or on liquid samples
-counting chamber with squares etched on a slide used for liquid samples
-you do not know if they are alive or dead
-hard to have accurate precision
-not consistent
-can have broken cells

Answer 13

total cell count

Question 14

What are the different growth phases?

Answer 14

-lag- introducing bacteria
-exponential- binary fission
-stationary- balance of chilling and reproducing
-decline- some level where there may not be enough nutrients

Question 15

What are the steps of binary fission?

Answer 15

-cell elongates and DNA is replicated
-cell wall and plasma membrane begin to constrict
-cross-wall forms completely separating the two DNA copies
-cells separate

Question 16

What is the symbol for generation time?

Answer 16

g

Question 17

What is the symbol for time?

Answer 17

t

Question 18

What is the symbol for cell number at time?

Answer 18

Nt

Question 19

What is the symbol for starting cell number?

Answer 19

N0

Question 20

What is the symbol for number of generations?

Answer 20

n

Question 21

What is the symbol for specific growth rate?

Answer 21

k

Question 22

Psychrophilic

Answer 22

like it cold, they wont grow well past 10 degrees

Question 23

mesophile

Answer 23

broad range, thrive at body temp

Question 24

thermophile

Answer 24

high temp

Question 25

Hyperthermophile

Answer 25

really high temp

Question 26

Optimal ph refers to what?

Answer 26

extracellular only

Question 27

The intracellular ph must stay relatively close to neutral consistent with what?

Answer 27

macromolecule stability

Question 28

Microbial culture typically contains buffers to maintain what?

Answer 28

constant ph

Question 29

-what causes plasmolysis because of hypertonic environments, required by extreme or obligate halophiles, and tolerated by facultative halophiles

Answer 29

high osmotic pressure

Question 30

grows very well in high salt concentrations

Answer 30

halophile

Question 31

can grow with salt but does not have to

Answer 31

halotolerant

Question 32

not much salt at all

Answer 32

nonhalotolerant

Question 33

can grow when osmotic concentrations are really high

Answer 33

osmophile

Question 34

can grow really well when dry

Answer 34

zerophile

Question 35

What are the enzymes that destroy toxic oxygen species like superoxide, hydrogen peroxide, and hydroxyl radical?

Answer 35

catalase, peroxidase, superoxide dismutase, combination of catalase and superoxide dismutase, and superoxide reductase

Question 36

oligate aerobe

Answer 36

requires oxygen

Question 37

facultative aerobe

Answer 37

not required but grows better with oxygen

Question 38

microaerophilic aerobe

Answer 38

required but at levels lower than atmospheric

Question 39

aerotolerant anaerobe

Answer 39

not required and grows no better with oxygen present

Question 40

obligate anaerobe

Answer 40

harmful or lethal