Lab Quiz #3

Question 1

4 things a culture medium must provide

Answer 1

Carbon source
Nitrogen source
Energy source
pH stability

Question 2

Defined medium is also called what?

Answer 2

Synthetic medium

Question 3

Defined medium definition

Answer 3

Medium in which components are known

Question 4

When would defined medium be useful?

Answer 4

Studying metabolism of a microorganism

Question 5

Complex medium is also called what?

Answer 5

Undefined medium

Question 6

Complex medium definition

Answer 6

Medium that contains some ingredients of unknown composition

Question 7

When is complex medium useful?

Answer 7

Need to satisfy nutritional requirements of many microorganisms or if microorganism’s nutritional requirements are unknown

Question 8

General purpose medium

Answer 8

Allows growth of many microorganisms

Question 9

Enrichment medium

Answer 9

Selects microorganisms of highest growth rate amongst a microbial population

Question 10

Selective medium

Answer 10

Favors growth of particular organism

Question 11

Differential medium

Answer 11

Distinguishes between different groups of bacteria

Question 12

Agar functions as what and is isolated from what?

Answer 12

Hardening or solidifying agent

Red algae

Question 13

Sterilization

Answer 13

Complete removal or destruction of all living cells, viruses, and spores from a medium or object

Question 14

What 3 physical agents are used in sterilization?

Answer 14

Heat
Filtration
Radiation

Question 15

Autoclave

Answer 15

Used to sterilize objects and media using saturated steam under high pressure

Question 16

Standard conditions for autoclaving

Answer 16

121 degrees Celsius
15 psi
15 minutes

Question 17

Beef extract is prepared how?

Answer 17

Water infusion of lean ground beef

Question 18

Beef extract contains what?

Answer 18

Amino acids
Peptides
Nucleotides
Organic acids
Vitamins 
Minerals

Question 19

Tryptone is prepared how?

Answer 19

Partial digestion or hydrolysis of protein casein by enzyme trypsin

Question 20

Tryptone contains what?

Answer 20

Peptides and amino acids

Question 21

Yeast extract is prepared how?

Answer 21

Aqueous extraction of brewer’s yeast solids

Question 22

Yeast extract contains what?

Answer 22

B vitamins
Nitrogen
Carbon

Question 23

Potassium phosphate is used for what?

Answer 23

pH buffer

Question 24

Ingredients for GTYE agar

Answer 24

Glucose
Tryptone
Yeast extract
Beef extract
K2HPO4
KH2PO4

Question 25

Steps of ELISA

Answer 25

1. Antigen is nonspecifically adsorbed to wells of 96 well plate
2. Further nonspecific binding is prevented by washing with detergent and/or blocking with horse serum
3. Dilutions of serum containing antibodies are added to wells
4. Plate is washed
5. Seondary antibodies covalently bound to colorimetric enzyme are added
6. Plate is washed
7. Substrate is added for enzyme reaction

Question 26

Enzyme conjugated to secondary antibodies used in ELISA

Answer 26

Horseradish peroxidase

Question 27

HRP uses what substrate to oxidize what indicator? What is the color change seen when reaction is complete?

Answer 27

Hydrogen peroxide (substrate)
O-phenylenediamine (indicator)
Changes from colorless to yellow-brown

Question 28

2 types of enzymes used to break up OVA

Answer 28

Cyanogen bromide (CNBr)
Trypsin

Question 29

Which of the 2 enzymes used to break up OVA produces smaller fragments?

Answer 29

Trypsin