Lab Final

Question 1

___________: proteins that function as biological catalysts for cellular chemical reactions

Answer 1

Enzymes

Question 2

Biochemical tests use chemicals called ____________ that produce visible evidence of some form to indicate that a specific biochemical reaction has occurred

Answer 2

Reagents

Question 3

What is the objective of the amylase test?

Answer 3

to determine if your unknown organism can catabolite amylose (starch)

Question 4

Small monosaccharides that bacteria use as energy sources can easily pass through the cell membrane, often by way of specific ___________

Answer 4

Transporters

Question 5

Small monosaccharides are catabolized inside the cell by __________________ ________________

Answer 5

Intracellular enzymes

Question 6

Why do sugars need to be hydrolyzed into monosaccharides?

Answer 6

They are too bulky to be transported into the cell by specific transporters

Question 7

What enzyme hyrdolyzes starch?

Answer 7

Amylase

Question 8

Amylase and Maltase are _____-cellular enzymes that hydrolyze amylose into glucose

Answer 8

Extra

Question 9

Starch turns into _______ with the help of _______ which then turns into _______ with the help of _________

Answer 9

Starch turns into maltose with the help of amylase, which then turns into glucose with the help of maltase

Question 10

Bacteria that live in ______ are often capable of starch hydrolysis since starch is an abundant nutrient in soil

Answer 10

Starch

Question 11

Starch reacts with _________ to produce a chemical complex that is dark blue or red brown

Answer 11

Iodine

Question 12

What are the physical, positive results of the amylase test? What is the negative test result?

Answer 12

The positive amylase result will appear clear, and the negative amylase result will interact with the starch left in solution and appear dark in color

Question 13

What is deanimation? What is the enzyme involved?

Answer 13

Deamination is an organisms ability to remove an amino acid from a molecule by using the enzymes deanimases

Question 14

What is a decarboxylation? What is the enzyme involved?

Answer 14

The removal of the carboxyl group and the removal and modification of the R-side chains. The enzyme used is decarboxylase.

Question 15

What is the goal of the cysteine desulfhydrase?

Answer 15

To determine if your unknown organism expresses cysteine desulfhydrase to catabolize cysteine

Question 16

The first step in the biochemical pathway used to catabolize cysteine is the removal of _______________________

Answer 16

part of the R-group

Question 17

What is the enzyme used to remove the R-group?

Answer 17

Cysteine desulfhydrase

Question 18

What gas is released when the -SH is removed from the R group?

Answer 18

H2S (hydrogen sulfide gas)

Question 19

Cysteine and water are converted by cysteine desulfhydrase into?

Answer 19

Alanine and Hydrogen Sulfide

Question 20

How is cysteine digestion detected?

Answer 20

By the production of H2S

Question 21

How is the production of H2S in cysteine digestion detected?

Answer 21

The interaction between iron ions and H2S will form a black substance

Question 22

What color does the medium used in cysteine digestion starts out being, what color does it turn if cysteine digestion is occurring?

Answer 22

Yellow/cream to black

Question 23

What is the objective of the lysine decarboxylase?

Answer 23

To determine if your unknown organism expresses lysine decarboxylase to catabolize lysine

Question 24

The removal of a carboxyl group always results in the production of ______ gas and ________

Answer 24

CO2 and amine, cadverine

Question 25

How do the products of lysine decarboxylase react with the bromcresol purple indicator?

Answer 25

Products make the solution more basic, which causes the indicator to be purple.

Question 26

What are the variations of bromcresol purple under basic, neutral, and acidic conditions?

Answer 26

basic- purple Neutral- brown Acidic- yellow

Question 27

What is the objective of urea digestion?

Answer 27

To determine if an organism expresses urease to catabolize urea

Question 28

Ammonia is transported to the liver and converted into _______

Answer 28

Urea

Question 29

Some bacteria can extract energy from ______ by converting it back into ammonia and CO2

Answer 29

Urea

Question 30

What enzyme assists in the conversion of urea to ammonia?

Answer 30

Urease

Question 31

What is the reagent of the Urease test? How does this test indicate a a positive or negative?

Answer 31

This urease test uses phenol red as the reagent. This test when positive for urea digestion turns red/pink

Question 32

What is the color of the urea broth?

Answer 32

The urea broth has a pH of 6.8 which makes it straw-yellow.

Question 33

What is the objective of the gelatin hydrolysis?

Answer 33

to determine if your unknown organism expresses gelatinase to digest gelatin

Question 34

What is the extracellular enzyme that hydrolyses gelatin into peptides?

Answer 34

gelatinase

Question 35

Why is it important to study whether a mo can hydrolysize gelatin at low temperatures?

Answer 35

Gelatin will naturally liquify at 37 degrees so it is important to avoid a false positive

Question 36

What is the positive/negative of the amylase test?

Answer 36

(+)= clear zone if the mo produced amylase and hydrolysized the starch there will be no starch to interact with the iodine (-)= dark purple color The mo does no hydrolyze the starch and therefore iodine will interact with the starch

Question 37

What are the positive and negative tests of Cysteine Desulfhydrase?

Answer 37

Positive- black precipitate | Negative- no black precipitate

Question 38

What is the postive and negative results for a lysine decarboxylase?

Answer 38

Positive: purple Negative: brown/yellow

Question 39

What are the positive and negative results of a Urea digestion test?

Answer 39

Positive- bright pink | Negative- no pink color

Question 40

What are the results of gelatin hydrolysis?

Answer 40

Postive-liquid medium | Negative- solid medium

Question 41

What differentiates staphylococci and streptococci?

Answer 41

The catalase tests. Strep are catalase negative. Staph are catalase positive.

Question 42

How do we differentiate between staphylococci and micrococci?

Answer 42

Oxidase test. | Staphylococci are negative for this test and strep are positive for this test.

Question 43

Staphylococcus epidermis are not pathogenic but can cause __________ ______________ under some circumstances

Answer 43

opportunistic infections

Question 44

Staphylococcus aureus is a _____________ _______________ that causes diseases in even healthy individuals

Answer 44

Primary pathogen

Question 45

A primary pathogen is largely due to the many ____________ ___________

Answer 45

Virulence factors

Question 46

What are the four characteristics of S. Aureus that are useful for identification?

Answer 46

1. Coagulase 2. Fermentation of mannitol 3. Heat-stable deoxyribonuclease (DNase) 4. Beta hemolysis

Question 47

S.aureus is also is most often an _________________ rather than an infection?

Answer 47

Intoxication

Question 48

___________ is a selective medium, it contains 7.5% NaCl which inhibits the grow of halo tolerant organisms but allows growth of halophiles

Answer 48

MSA

Question 49

MSA is selective for what?

Answer 49

Staphylococci

Question 50

MSA is a differential medium. T or F?

Answer 50

T

Question 51

What type of indicator is used within a test of fermentation fo mannitol? How does this indicate the positive or negative test?

Answer 51

Phenol red | This turns colonies that ferment the mannitol to yellow

Question 52

DNase agar is differential. T or F?

Answer 52

T

Question 53

DNase agar is not selective. T or F?

Answer 53

T

Question 54

What materials are found within the DNase agar?

Answer 54

A rich source of nutrients, agar, methyl green as an indicator and large DNA molecules

Question 55

What is the importance of the methyl green indicator within a DNase agar?

Answer 55

Methyl green

Question 56

How does methyl green interact with DNase production?

Answer 56

Methyl green interacts with the large DNA molecules and forms a green complex The absence of these DNA molecules becomes a colorless compound

Question 57

A complete hydrolysis of red blood cells is called ______________

Answer 57

Beta-hemolysis

Question 58

What is the partial lysis of RBC called?

Answer 58

Alpha hydrolysis

Question 59

What is the complete lysis of RBC called?

Answer 59

Gamma hydrolysis

Question 60

If the bacteria in question is susceptible to antibiotics there will be a _____________ ________________

Answer 60

Zone of inhibition

Question 61

Microbial growth

Answer 61

An increase in the # of bacterial cells over time

Question 62

Viral titer

Answer 62

The concentration of viral particles in a sample

Question 63

The most widely used procedure for measuring the titer is the __________ ____________

Answer 63

Plaque assay

Question 64

it uses grow inside a susceptible _______ cell

Answer 64

Host

Question 65

The viral tiger is measured as the number of plaques that form on the lawn of host cells and it’s referred as the # of ______________ ____________ _______________

Answer 65

Plaque forming units

Question 66

The number of PFU should be equal to the # ___________ _________

Answer 66

Of viral particles in the sample

Question 67

___________ agar: is a bacterial growth medium with only 0.75% agar instead of the normal 1.5%

Answer 67

Top

Question 68

How do you calculate the # of PFU/mL?

Answer 68

plaques x dilution factor/ mL of phage plated

Question 69

How to calculate the total # of PFU units in the original sample

Answer 69

(PFU/mL)x the total volume in the original sample (mL)

Question 70

Microorganisms that have adapted to living symbiotically on or in our bodies without causing disease are called __________

Answer 70

Commensals

Question 71

Other terms for the collective group of symbiotic microorganisms that live on our bodies are ____________ flora and _____________ flora

Answer 71

Resident and indigenous

Question 72

____________ is a relationship between two organisms of different species living together in a close and permanent association

Answer 72

Symbiosis

Question 73

Who proposed Germ Theory of Disease?

Answer 73

Koch and Pasteur

Question 74

______________: are microbes that are picked up from the environment temporarily and are not permanent residents of the microbial flora

Answer 74

Transient microbes

Question 75

The ability of chemicals to damage pathogens without damaging human tissue is called ______________ ______________

Answer 75

Selective toxicity

Question 76

______________: chemicals produced by a microorganism that inhibit the growth of or kill other mo

Answer 76

Antibiotics

Question 77

Antibiotics that are effective only against either gram positive or gram negative organisms are called ____________ ______________ antibiotics

Answer 77

Narrow-spectrum

Question 78

Antibiotics that are effective against both gram negative and gram positive are referred to as _____________ ____________ antibiotics

Answer 78

Broad-spectrum

Question 79

Penicillin is a ______ spectrum antibiotic

Answer 79

Broad

Question 80

The way that antibiotics affect the bacteria is known as _________ ___________

Answer 80

Mechanisms of action

Question 81

Antibiotics that kill bacteria are called ________________

Answer 81

Bactericidal

Question 82

Antibiotics that inhibit their growth are called _________________

Answer 82

Bacteriostatic

Question 83

One of the most widely used tests to determine the sensitivity of a microbe to a specific antimicrobial agent is a ___________ ___________ test

Answer 83

Disk diffusion

Question 84

What is a standardized form of a disk diffusion test?

Answer 84

Kirby-Bauer

Question 85

If the microbe is affected by the antimicrobial it will not grow near the disk, producing a _____________________________

Answer 85

Zone of inhibition

Question 86

The larger the zone of inhibition, the _______ sensitive the microbe is to that antibiotic

Answer 86

More

Question 87

In a Kirby Bauer test what depth is required for the agar plate?

Answer 87

4mm

Question 88

__________: are proteins produced by the B-lymphocytes of the immune system that have many functions in the protection against pathogens

Answer 88

Antibodies

Question 89

Any molecules that is deemed as “foreign” and activates the immune system is called an _________

Answer 89

Antigen

Question 90

The study of antigen-antibody interactions is called ____________

Answer 90

Serology

Question 91

_________ is the clear liquid portion of the blood that remains after the blood is allowed to clot

Answer 91

Serum

Question 92

___________ is the liquid portion of the blood including clotting proteins

Answer 92

Plasma

Question 93

What is the difference between plasma and serum?

Answer 93

Plasma contains clotting proteins and serum does not

Question 94

What is the similarity between plasma and serum?

Answer 94

Contain antibodies but lack blood cells

Question 95

The concentration of antibody against a particular antigen is referred to as the ___________

Answer 95

Titer

Question 96

The ______ test is a slide agglutination test used to diagnose salmonella infections

Answer 96

Widal