Unit 4 Lab Exam

Question 1

How do heterotrophs get carbon

Answer 1

from organic compounds

Question 2

How do autotrophs get carbon

Answer 2

CO2

Question 3

What are common carbon energy sources in this class

Answer 3

sugars–glucose or lactose
amino acids and peptides
organic acids, polyols, or alcohols–citrate, fatty acids, succinate or glycerol

Question 4

What can supply nitrogen

Answer 4

amino acids, inorganic ammonium or nitrate salts

Question 5

What can supply sulfur or phosphorus

Answer 5

inorganic salts such as magnesium sulfate or potassium phosphate

Question 6

Define growth factor

Answer 6

specific organic compound that is required by a particular organism, as it cannot be synthesized by that organism

Question 7

Organisms termed ________ tend to require a variety of growth factors

Answer 7

fastidious

Question 8

What does a defined medium mean

Answer 8

the exact chemical composition of a culture medium is known

Question 9

What does complex medium mean

Answer 9

the exact chemical composition is not known; and such a medium is often prepared from complex materials such as tissues or infusions

Question 10

Define rich medium and our primary e.g.

Answer 10

when a medium contains an abundance of nutrients of all types; NB

Question 11

Liquid media AKA ______ contain all the needed nutrients and is generally used to grow microbes through tubes and flasks

Answer 11

broth

Question 12

What is the most common solidifying agent added to a liquid medium to become solid

Answer 12

agar

Question 13

What is the purpose of buffers

Answer 13

chemicals that are incorporated to maintain a favorable pH range of the medium during growth

Question 14

E.g. of buffers

Answer 14

sodium and potassium phosphate
calcium carbonate
peptones

Question 15

extracts are used as a source of ______ _______

Answer 15

amino acids

Question 16

peptones contain _______ and single __ ______

Answer 16

peptides; amino acids

Question 17

e.g. of peptones

Answer 17

tryptose, tryptone, proteose peptone, peptone

Question 18

peptone solutions will support the growth of ______ organisms because of what

Answer 18

many; the source of amino acids

Question 19

Define pH indicator

Answer 19

a pH indicator is often added to differential media to detect pH changes in the medium

Question 20

What are e.g. of pH indicators

Answer 20

brom cresol purple, brom thymol blue, phenol red

Question 21

What color will the indicators turn if it is acidic

Answer 21

yellow color

Question 22

What color does neutral red turn at acidic pH

Answer 22

red

Question 23

What is a reducing agent

Answer 23

certain chemicals may stimulate growth by reducing the oxidation-reduction potential in the environment

Question 24

e.g. of reducing agents

Answer 24

Cysteine and thioglycolate

Question 25

what is a selective agent

Answer 25

antimicrobial agens can be employed in selective media to suppress or inhibit the growth of certain groups of microbes while allowing growth of desired organisms

Question 26

Do selective agents kill unwanted organisms?

Answer 26

no

Question 27

what is rich media

Answer 27

provides excess nutrients over the minimum require

Question 28

What is the use of rich media

Answer 28

used when microbe is fastidious or we want more rapid growth

Question 29

What is the use of defined media

Answer 29

physiological studies of organisms for determining the exact nutritional needs of an organism

Question 30

What is non selective medium

Answer 30

it doesn't deliberately support the growth of one microbe over the other (allows many to grow)

Question 31

What is the use of non selective medium

Answer 31

growth of a wide variety of organisms

Question 32

What is the use of selective medium

Answer 32

isolation and growth of a specific culture type of microbe from a mixed culture

Question 33

What is all purpose medium

Answer 33

non-selective, supports a wide variety of organisms

Question 34

What is differential medium

Answer 34

contains ingredients that allow us to visually differentiate between different types of microbes

Question 35

What is the use of differential medium

Answer 35

visual identification of a type of microbe based on colony appearance

Question 36

What are e.g. of all purpose rich, complex medium

Answer 36

PCA, NA, Yeast extract tryptone glucose

Question 37

What is the difference between enrichment media and selective media

Answer 37

enrichment media are those that favor the growth of certain microbes selective media supports the growth of desired organism while inhibiting the growth of many of the unwanted ones

Question 38

What are examples of selective media

Answer 38

MAC nitrogen free broth succinate broth azide containing media

Question 39

What are the selective ingredients in MAC

Answer 39

bile salts and CV that inhibit most gram positive bacteria

Question 40

What are e.g. of differential media

Answer 40

MAC and EMB

Question 41

What type of growth will obligate aerobes have

Answer 41

growth at the top of the tube where there is oxygen

Question 42

What do obligate aerobes grow in

Answer 42

posses only a respiratory type of metabolism and use oxygen as the terminal electron acceptor

Question 43

Where will obligate anaerobes grow

Answer 43

at the bottom of test tubes

Question 44

What do obligate anaerobes need to grow

Answer 44

02 is toxic so they need to be away from it

Question 45

How to facultative anaerobes grow

Answer 45

prefer O2 but can grow without it

Question 46

how do aerotolerant anaerobes grow

Answer 46

prefer no O2 but can grow with it

Question 47

Where will anaerobic respirers grow

Answer 47

no growth at all in the tube

Question 48

If fermentation occurs in a neutral pH with the color purple to begin what color will it turn

Answer 48

yellow

Question 49

Are MAC and EMB sharing the following features contain pH sensitive dye ingredients inhibits the growth of gram negative bacteria differential for glucose fermentation contain peptone as a nitrogen source

Answer 49

T F F T

Question 50

How does fermentation work

Answer 50

make ATP using only substrate level phosphorylation as a method

Question 51

Does fermentation produce large amounts of waste products

Answer 51

yes

Question 52

What is respiration

Answer 52

making ATP using the ETC and proton motive force

Question 53

What are the examples of selective media that help determine physiological characteristics

Answer 53

glucose fermentation motility Thioglycolate EMB agar

Question 54

For MAC what ingredients are selective agents

Answer 54

bile salt and CV

Question 55

For MAC what ingredients are differential agents

Answer 55

neutral red and lactose

Question 56

What bacteria type is inhibited by the bile salts and CV in MAC

Answer 56

gram positive

Question 57

What color does MAC look when fermentation has occured

Answer 57

red

Question 58

How long can MAC be incubated for

Answer 58

24 hours

Question 59

Mobility has occurred when microbes can move ________ the line of inoculation

Answer 59

away

Question 60

Mobility can be seen when a tube has _________-

Answer 60

turbidity

Question 61

What type of bacteria does EMB agar detect and identify

Answer 61

enteric bacteric

Question 62

What does the Eosin Y and Methylene blue dyes inhibit

Answer 62

gram positive bacteria and dyes combined with lactose allow for differentiation between lactose fermenters and lactose non-fermenters

Question 63

With the NA agar, what did...look like E. coli P. fluorescens S. epidermidis

Answer 63

milky color, irregular colony, undulate, smooth yellow color, irregular colony, undulate, rought white color, circular, entire edge, smooth

Question 64

What bacteria had no growth in the MAC E. coli P. fluorescens S. epidermidis

Answer 64

S. epidermidis