Lab Practical 1

Question 1

Pure culture

Answer 1

Contains only one species of microorganism

Question 2

Mixed culture

Answer 2

Another species of microorganism is accidentally introduced into a pure culture, the culture is said to be contaminated

Question 3

Sterilization

Answer 3

The destruction or removal of all forms of microorganisms

Question 4

Aseptic technique

Answer 4

The methods of obtaining and maintaining pure cultures

Question 5

Selective media

Answer 5

Contain at least one ingredient that can inhibit the growth of unwanted microorganisms without preventing the growth of the desired type.

Question 6

Selective agents

Answer 6

Ingredients that inhibit the growth of unwanted organisms

Question 7

Differential media

Answer 7

Designed to distinguish one type of microorganism from all others in a mixed culture

Question 8

Mannitol-salt agar

Answer 8

A medium of selective and differential
Selective because it has sodium chloride
Differential because it contains both mannitol (six carbon sugar alcohol) and phenol red (a pH indicator)
With MSA you can distinguish between fermenting and non fermenting staphylococci

Question 9

Optimum growth temperature

Answer 9

The temperature at which growth rate is the highest

Question 10

Mesophilic

Answer 10

Microorganisms with the optimum growth rates between 28 degrees and 38 degrees Celsius

Question 11

Psychrophilic

Answer 11

Microorganisms with the optimum growth rates at temperatures below 16 degrees Celsius

Question 12

Thermophilic

Answer 12

Microorganisms with the optimum growth rate around 60 degrees Celsius
G. S

Question 13

Maximum growth temperature

Answer 13

The highest temperature at which growth occurs

Question 14

Minimum growth temperature

Answer 14

The lowest temperature at which growth occurs

Question 15

Obligate anaerobes

Answer 15

Require no oxygen for growth

Oxygen is toxic to these bacteria

Question 16

Aerobe

Answer 16

Grow only when oxygen is present

Question 17

Facultative anaerobes

Answer 17

Can grow either in the presence or absence of oxygen

Question 18

Extracellular enzymes

Answer 18

Enzymes released by the cell

Question 19

Hydrolytic enzymes

Answer 19

Break up large molecules

Question 20

Protease

Answer 20

Break apart proteins

Amino acids

Question 21

Amylase

Answer 21

Break apart polysaccharides or starch

Sugars

Question 22

Lipase

Answer 22

Break apart lipids

Fatty acids

Question 23

Binding protein

Answer 23

Dictate the kind of small molecules that enter the cell

Question 24

Translocation

Answer 24

The movement of molecules across the membrane

Question 25

Monosaccharides

Answer 25

The five or six-carbon sugars

Question 26

Oligosaccharides

Answer 26

Larger molecules composed of two or more monosaccharide units joined by glycosidic bonds

Question 27

Polysaccharides

Answer 27

Larger polymers of monosaccharide units joined together by glycosidic bonds

Question 28

Cellulose

Answer 28

Composed of long, unbranched chains of glucose units connected by beta glycosidic bonds

Question 29

Cellulase

Answer 29

Can break down cellulose

Question 30

Nutrient polysaccharides

Answer 30

Formed by both animal and plant cells and they are used to reserve food supplies by the cells that form them.

Question 31

Glycogen

Answer 31

The reserve polysaccharide of animal cells

Question 32

Starch

Answer 32

Similar to glycogen in animal cells, but for plant cells. Reserve polysaccharide

Question 33

Amylose

Answer 33

A straight chain made of only glucose molecules connected by alpha glycosidic bonds

Question 34

Amylopectin

Answer 34

Contains only glucose by similar bonds in amylose, but it’s structure is branched.

Question 35

Maltose

Answer 35

A disaccharide composed of two glucose units

Question 36

Zone of hydrolysis

Answer 36

Results from the enzymatic breakdown of the insoluble starch into smaller oligosaccharides and the disaccharide maltose

Question 37

Gelatin deeps

Answer 37

Used in lab to demonstrate gelatin hydrolysis

Question 38

IMViC

Answer 38

• Indole(Coli)
• Methyl Red(Coli)
• Vogues Proskauer(Aerogenes) A: 15 drops; B: 5 drops
• Citrate(Aerogenes)

Question 39

Complete clearing or destruction

Answer 39

Beta hemolysis

Question 40

Incomplete destruction

Answer 40

Alpha hemolysis
Green
Streptococcus Sanguis

Question 41

No reaction/no hemolysis

Answer 41

Gamma Hemolysis

Streptococcus salivarius

Question 42

Blood agar

Answer 42

TSA and 5% while blood

Differential media

Question 43

Fastidious

Answer 43

Microorganisms that have unusually complex nutrient requirements, a common trait among pathogenic species that are used to living in the body
Pathogenic species: Streptococcus pyogenes

Question 44

Sterilization

Answer 44

Absolute destruction or removal of a living organisms

Question 45

Starch agar

Answer 45

Can the microbe digest starch?

Bacillus cereus = yes

Question 46

Phenol red fermentation tubes

Answer 46

Ferment sugar?
Yes, what kind?
Lactose:
E. Coli= gas and acid
Enterococcus faecaus= neither
P. Mirabius= acid
Sucrose:
E. Coli=neither
Enterococcus faecaus= acid
P. Mirabius= acid
Glucose:
E. Coli= acid and gas
Enterococcus faecaus= acid 
P. Mirabius= neither

Question 47

Gelatin tubes

Answer 47

Can the microbe digest gelatin
E. Coli= no
B. Cereus= yes
Proteus vulgaris= no