MIDTERM

Question 1

a medium that contains living microbes is called a

Answer 1

culture

Question 2

a pure culture is

Answer 2

a culture that contains a single species

Question 3

what are broths used for

Answer 3

grow microbes when fresh cultures or large number of cells are required

Question 4

agar slats are used for

Answer 4

grow stock cultures that can be refrigerated after incubation

Question 5

plated media are used for

Answer 5

obtaining isolation of species

Question 6

a mixed culture is said to be

Answer 6

microbial culture made of two or more species

Question 7

_______ contains only a single species

Answer 7

pure culture

Question 8

commonly used isolation technique is

Answer 8

streak plate

Question 9

______ substances designed to reduce the number of pathogen on a surface liquid or living tissue

Answer 9

germicide

Question 10

germicides used on surfaces or in liquid are

Answer 10

disinfectants

Question 11

antiseptics are

Answer 11

germicides designed for use on living tissue

Question 12

a wet mount preparation is made by

Answer 12

placing specimen in drop of water on microscope slide and covering it with cover glass

Question 13

motility often can be observed at

Answer 13

low or high dry magnification

Question 14

hanging drop preparation allows for

Answer 14

longer observation of specimen because it does not dry out as quickly

Question 15

the primary stain in gram stain is

Answer 15

crystal violet

Question 16

what is purpose of iodine

Answer 16

mordant to enhance crystal violet staining by forming crystal violet iodine complex

Question 17

what follows after iodine added

Answer 17

decolorization

Question 18

gram positive cells are what color

Answer 18

purple

Question 19

gram negative cells are what color

Answer 19

red/pink

Question 20

gram negative cells can be colorized by

Answer 20

counterstain safranin

Question 21

what does phenol red indicate

Answer 21

if fermentation with an acid end product has taken place by chains color as the pH changes

Question 22

what grows on MSA (mannitol salt agar)

Answer 22

most staphylococci

Question 23

staphylococcus aureus ferments

Answer 23

mannitol

Question 24

the oxidation fermentation test is designed to

Answer 24

differentiate bacteria on basis of fermentation or oxidative metabolism of carboyhydrates

Question 25

In OF test oxidative organism oxidize carbs to

Answer 25

CO2 H2O and energy

Question 26

oxidase test is designed to identify

Answer 26

the presence of cytochrome c oxidase

Question 27

a positive oxidase test gives the result

Answer 27

dark blue purple color

Question 28

what ETC molecules are unable to donate protons

Answer 28

flavoproteins, iron-sulfur proteins, and cytochromes

Question 29

what enzyme converts superoxide radicals to hydrogen peroxide

Answer 29

superoxide dismutase

Question 30

catalase converts

Answer 30

hydrogen peroxide to water and O2

Question 31

a positive catalase test gives what result

Answer 31

bubbles

Question 32

negative catalase test gives what result

Answer 32

no bubbles

Question 33

what gives chromogen its color

Answer 33

chromophore