Lab Exam 1

Question 1

Place one drop of water in the center of the slide, transfer small amount of bacterial inoculum from the culture, spread into the size of a nickel, Air dry, heat fix.

Answer 1

Preparation of bacterial smears from solid medium

Question 2

Wet mount

Answer 2

Determine how to do a wet mount

Question 3

Let slide dry, heat fix, apply stain (1 to 2 minutes), gently wash with tapwater, blot slide with bibulous paper

Answer 3

Simple staining Crystal violet 20 to 60 seconds

Question 4

Place a drop of Negrosin at one end of the slide, place loop full of inoculum in the drop, mix, place slide against the drop at 45° angle and spread, Air dry.

Answer 4

Negative staining

Question 5

Prepare a slide (Inoculum, water, smear, heat fix). Flood slide with crystal violet. One minute. Wash with tapwater (Still purple). Flood slide with gram’s iodine. One minute. Wash with tapwater. Decolorize with ethyl alcohol (Almost clear). Wash with tapwater. Counterstain with saffranin for 45 seconds. Wash with tapwater. Blot dry.

Answer 5

Gram staining

Question 6

The bending power of light passing through air from glass slide to objective lens

Answer 6

Retractive index

Question 7

When one lenses and focus, the other lenses will also have the same focal length, and can be rotated into position without further major adjustment.

Answer 7

Parfocal

Question 8

Vibratory movement of the cells due to their bombardment by water molecules in the suspension

Answer 8

Brownian movement

Question 9

Pair of cocci

Answer 9

Diplococcus

Question 10

Chain of cocci

Answer 10

Streptococcus

Question 11

Cluster of cocci

Answer 11

Staphylococcus

Question 12

Packet of four cocci

Answer 12

Tetrad

Question 13

Packet of eight cocci

Answer 13

Sarcina

Question 14

Rod shaped, pair

Answer 14

Diplo bacillus

Question 15

Rod shaped chain

Answer 15

Streptobacillus

Question 16

Spiral bacteria, curved rods

Answer 16

Vibrios

Question 17

Spiral, helical and Rigid

Answer 17

Spirilla

Question 18

Spiral bacteria, helical and flexible

Answer 18

Spirochetes

Question 19

Two Loopfulls of the cell suspension, spread suspension, allow the smear to air dry, heat fix.

Answer 19

Preparation of bacterial smears from broth medium

Question 20

Requires the use of at least four chemical reagents that are applied sequentially to heat fixed smear

Answer 20

Differential staining

Question 21

Imparts it’s color to all cells, Crystal violet

Answer 21

Primary stain

Question 22

Killing agent, increases the cells affinity for a stain, Used to intensify the color of the primary stain, grams iodine

Answer 22

Mordant, Crystal – Violet – iodine complex CV –I

Question 23

Protein dehydrating agent and lipid solvent. In gram-negative cells, the alcohol increases the porosity of the cell wall by dissolving the lipids in the outer layer. CV – I complex is washed out. Gram-positive cells retain CV – I complex do you to thicker peptidoglycan. May or may not remove the primary stain from the entire cell or for only certain cell structures.

Answer 23

Decolorizing agent, ethyl alcohol

Question 24

Contrasting color to that primary stain. Gram-negative.

Answer 24

Counterstain, safranin

Question 25

Divides bacterial cells into two major groups, gram-positive and gram-negative

Answer 25

Gram stain

Question 26

Malachite green

Answer 26

Used to stain free spores with impervious coats

Question 27

Used to isolate specific groups of bacteria. They incorporate chemical substances that inhibit the growth of one type of bacteria while permitting growth of another, thus facilitating bacterial isolation.

Answer 27

Selective media (Phenylethyl alcohol auger, crystal violet auger, 7.5% sodium chloride auger)

Question 28

Distinguish among morphologically and biochemically related groups of organisms.

Answer 28

Differential/selective media (macconkey agar, mannitol salt auger (staphylococci), eosin-methylene blue auger)

Question 29

7.5% sodium chloride selects for staphylococci

Answer 29

Mannitol salt auger (differential selective)

Question 30

Crystal violet allows the isolation of gram-negative bacteria by inhibiting gram-positive organisms

Answer 30

Macconkey agar (differential selective)

Question 31

Lactose and dyes permit differentiation between enteric lactose fermentors and non-fermenters as well as the identification colon bacillus E. coli.

Answer 31

Eosin-methylene blue auger (differential/selective media)

Question 32

Highly nutritious Materials for fastidious organisms. Blood, serum, or yeast extract.

Answer 32

Enriched media

Question 33

Permits the demonstration of hemolytic properties particularly streptococci

Answer 33

Blood agar (enriched media)

Question 34

No lysis of red blood cells

Answer 34

Gamma hemolysis, enriched media, blood agar

Question 35

Incomplete lysis of red blood cells, greenish halo around bacterial growth.

Answer 35

Alpha hemolysis, enriched media, blood agar

Question 36

Lysis of red blood cells, clear zones surrounding the colonies.

Answer 36

Beta hemolysis, enriched media, blood agar

Question 37

Non-antigenic oxygen stable lysin

Answer 37

Streptolysin S

Question 38

Use both aerobic and anaerobic pathways, fermentors of carbohydrates, degradation of glucose by the way of the glycolytic pathway

Answer 38

Facultative anaerobes

Question 39

Inverted vile for the detection of gas production in fermentation

Answer 39

Durham tube

Question 40

Design to differentiate among different groups of Enterobacteriaceae. All gram-negative bacilli capable of fermenting glucose with the production of acid and Gram-negative intestinal bacteria. (Differences in carbohydrate fermentation patterns and hydrogen sulfide production).

Answer 40

Triple sugar – iron auger test

Question 41

Aerobic and anaerobic

Answer 41

Cellular respiration

Question 42

Bioxidations in which molecular oxygen can serve as the final electronic acceptor

Answer 42

Aerobic

Question 43

Bioxidations in which inorganic ions other then oxygen such as nitrate (no3-) or sulfate (so4 2-) can serve as the final electronic acceptor

Answer 43

Anaerobic

Question 44

A bioxidative process not requiring oxygen in which an organic substrate serves as the final electronic acceptor, produces an organic acid that may be accompanied by gases, facultative anaerobes are usually fermenters of carbohydrates

Answer 44

Fermentation

Question 45

Nutrient broth ingredients for all organisms, specific carbohydrate, pH indicator

Answer 45

Carbohydrate fermentation medium

Question 46

Fermentation

Answer 46

Net two ATP, alcohol, lactic acid (in animals and some organisms)

Question 47

One glucose to two pyruvic acid to Krebs cycle

Answer 47

Glycolytic pathway

Question 48

Lack of carbohydrate fermentation. Alternative nutrients can be used as energy sources. These reactions liberate ammonia producing an alkaline environment. Phenyl red turns deep red in it now basic medium indicates aerobic respiration.

Answer 48

Peptones

Question 49

Alkaline slant (red) and acid butt (yellow) with or without gas production (breaks in the auger butt)

Answer 49

Results of triple sugar iron auger test, glucose fermentation only, peptones used in the production of alkali

Question 50

Acid slant (yellow) and acid butt (yellow) with or without gas production.

Answer 50

Results of the triple sugar iron Auger test, lactose and or sucrose fermentation

Question 51

Alkaline slant (red) and alkaline butt (red) or no change (Orange – red) butt

Answer 51

Results of the triple sugar iron auger test, no carbohydrate fermentation, peptones catabolized under anaerobic and or aerobic conditions create ammonia.

Question 52

A substrate for hydrogen sulfide production, blackening in the butt because of the precipitation of the insoluble ferrus sulfide

Answer 52

Sodium thiosulfate in TSI auger, indicates the production of h2s.

Question 53

Differentiation of the principal groups of Enterobacteriaceae. Indole, methyl red, voges – proskauer and citrate utilization

Answer 53

Imvic

Question 54

Determines the ability of microorganisms to degrade the amino acid tryptophan

Answer 54

tryptophanase and Indole production test

Question 55

Detects indole, cherry red reagent layer

Answer 55

Kovacs reagent

Question 56

Detect the presence of a large concentration of acid end products, ph 4, indicative of E. coli. PH 6 indicative of e. Aerogenes

Answer 56

Methyl red test

Question 57

Differentiates further along enteric organisms such as E. coli, E. Erogenes, and K. pneumoniae. Determines the production of nonacidic or neutral end products

Answer 57

Voges-proskauer test

Question 58

Barrett's reagent, pink complex formed imparting rose color to the medium, indicates acetylmethylcarbinal

Answer 58

Voges-proskauer test

Question 59

an organism can use citrate has its sole source of carbon. Indicates the presence of citrate permease, medium becomes alkaline, the carbon dioxide that is generated changes bromthemol blue indicator from green to Prussian blue

Answer 59

Citrate utilization test