Maxin’s Enzyme Exam 2 – Flashcards

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question
Breaks down starch (amylose)
answer
Amylase
question
Breaks down cysteine
answer
Cysteine Desulfhydrase
question
Breaks down Urea
answer
Urease
question
Breaks down Nitrate
answer

Nitrate reductase

;

question
Breaks down nitrite
answer
Nitrite reductase
question
Breaks down Gelatin
answer

Gelatin Hydrolysis

;

or

;

Gelatin hydrolase

;

or;

;

Gelatinase

question
Breaks down lactose
answer
Lactase
question
Breaks down sucrose
answer
Sucrase
question
Breaks down Dextrose
answer
Dextrase
question

The product of breakdown of starch (amylose) by amylase yields what?

;

answer
Glucose C6H12O6
question
Iodine is added to an innoculated starch agar plate and a dark blue/black zone appears. ;The organism is _____.
answer

Starch negative

;

(The organism did not break down the starch into glucose)

question

Iodine is added to an innoculated starch agar plate and a clear zone appears. ;The organism is _____.

answer

Starch positive

;

(The organism has the amylase enzyme which broke down the starch into glucose)

question
An innoculated triple sugar iron (TSI) agar slant turned black in the bottom of the tube. ;This organism is ______ and a(n)________.;
answer

Cysteine positive +

;

An anaerobe

;

(The organism contains the enzyme cysteine desulfhydrase which breaks down cysteine to yield Hydrogen Sulfide (H2S) which reacts with the iron in the agar to form a black precipitate.)

question

;

An innoculated triple sugar iron (TSI) agar slant turned black in the top of the tube. ;This organism is ______ and eats via ________.;

;

answer

;

Cysteine positive +

;

aerobic respiration

;

(The organism contains the enzyme cysteine desulfhydrase which breaks down cysteine to yield Hydrogen Sulfide (H2S) which reacts with the iron in the agar to form a black precipitate.)

;

question
An innoculated triple sugar iron (TSI) agar slant turned the entire tube black. ;This organism is ______ and gets its energy ________.;
answer

;

Cysteine positive +

;

Aerobically AND Anaerobically

;

(The organism contains the enzyme cysteine desulfhydrase which breaks down cysteine to yield Hydrogen Sulfide (H2S) which reacts with the iron in the agar to form a black precipitate.)

;

question
Cysteine is what type of molecule?
answer

Cysteine is an amino acid that contains sulfur.

;

(Think CySteine) S = Sulfur

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An innoculated triple sugar iron (TSI) agar slant is yellow. ;This organism is ______;?
answer
Cysteine negative -
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Innoculated Urea broth turned hot pink. ;The organism is urea ____.
answer

Urea positive

;

(The organism contains urease which breaks down the Urea into ammonia (NH3OH). ;Since ammonia is alkaline/basic, it turns the phenol red within the broth hot pink.)

question
Innoculated Urea broth is Urea +, what product formed to turn the broth hot pink?
answer
Ammonia NH3OH
question

Innoculated Urea broth turned yellow. ;The organism is urea ____.

answer

Urea negative -

;

(Phenol red in the broth turns yellow in acidic conditions, meaning the organism lacks the ability (enzyme: urease) into ammonia.)

question
Innoculated nitrate broth is treated with reagents sulfanilic acid and dimethylalphanaphthylamine. ;Which test is being performed?
answer
Nitrate reductase
question

;

Innoculated nitrate broth is treated with Nesslers' reagent. ;Which test is being performed?

;

answer
Nitrite reductase
question

1. Innoculated nitrate broth turns red with the addition of reagents;sulfanilic acid and dimethylalphanaphthylamine. ;The organism is _______?

;

2. What product caused the red color?

answer

1. Nitrate positive

;

2. Nitrite (NO2)

question
Innoculated nitrate broth is yellow with the addition of reagents;sulfanilic acid and dimethylalphanaphthylamine. ;The organism is _______?
answer
Nitrate negative
question

1. Innoculated nitrate broth is treated with Nesslers' reagent (aka HCl) and a yellow/brown precipitate forms. ;The organism is ______?

;

2. What is the product that forms the precipitate?

answer

1. Nitrite (NO2) positive

;

2. Ammonia (NH3 or N2)

;

(Nitrite reductase within the organism broke down Nitrite to Ammonia which combined with Nesslers to form Ammonium, the brown precipitate)

question
Innoculated nitrate broth is treated with Nesslers' reagent (aka HCl) and is yellow. ;The organism is ______?
answer
Nitrite negative -;
question

The same organism is innoculated into two tubes, A and B, containing Nitrate Broth. ;Sulfanilic acid and Dimethylalphanaphthylamine reagents are added to Tube A which yields a red color. ;Nesslers' reagent is added to Tube B and yields a yellow color.

This organism is nitrate ___ and nitrite ____?

answer

Nitrate positive

;

Nitrite negative

question

;

The same organism is innoculated into two tubes, A and B, containing Nitrate Broth. ;Sulfanilic acid and Dimethylalphanaphthylamine reagents are added to Tube A which yields a red color. ;Nesslers' reagent is added to Tube B and yields a brown precipitate.

What enzyme(s) does this organism possess?

;

answer

Nitrate reductase

;

and;

;

Nitrite reductase

question
An innoculated Tryptic Soy Gelatin tube is liquid after refrigeration. ;The organism is gelatin ______.
answer
Gelatin positive
question

;

An innoculated Tryptic Soy Gelatin tube turns to gel after refrigeration. ;The organism is gelatin ______.

;

answer
Gelatin negative
question

;

An innoculated Tryptic Soy Gelatin tube is liquid after refrigeration. ;The organism contains what enzyme?

;

answer

Gelatin hydrolase

;

(Gelatin hydrolase breaks down the gelatin so the conents of the tube can no longer solidify and so they remain liquid)

question
This test uses and inverted Durham tube in order to collect gas.
answer

Carbohydrate Fermentation

(Carbohydrase) Test

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This test can be used with any complex sugar (-ose)
answer

;

Carbohydrate Fermentation

(Carbohydrase) Test

;

(Carbohydrase breaks down complex sugars into glucose, to pyruvic acid, to carbon molecules, to acids and/or gases.)

;

question
Innoculated Phenol Red Lactose Broth turned yellow and has a bubble inside the Durham tube. ;The organism used _____ to produce _______.
answer

Lactase

;

Acid and Gas

;

(The organism is lactose positive + for acid and gas)

question

;

;

Innoculated Phenol Red Lactose Broth turned yellow and did not have bubble inside the Durham tube. ;The organism used _____ to produce _______.

;

;

answer

Lactase

;

Acid only

;

(Organism is Lactose positive for acid)

question

;

;

Innoculated Phenol Red Dextrose Broth turned yellow and had a bubble inside the Durham tube. ;The organism used _____ to produce _______.

;

;

answer

Dextrase

;

Acid and Gas

;

(Organism is dextrose positive +)

question
Innoculated Phenol Red Sucrose Broth turned red and had no bubble inside the Durham tube. ;The organism used _____ to produce _______.
answer

Trick question:

;

The organism is Sucrose negative - it does not contain sucrase and thefore could not break down the sucrose into acids nor gas.

question
Phenol red turns what color in acids
answer
Yellow
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Phenol red turns what color in base?
answer
Hot pink
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What four tests make up the IMViC tests?
answer

;

  • Indole (Tryptophanase)
  • Methyl Red;
  • Voges-Proskauer (Butanediol Dehydrogenase)
  • Citrate Utilization (Citrase)

;

question
The Indole (Tryptophanase) test uses this reagent.
answer
What is Kovacs' reagent
question

Innoculated 1% tryptone broth is treated with Kovacs' reagent. ;A red layer forms.;

1) What is this red layer?

2) What enzyme formed this product?

answer

1. Indole

2. Tryptophanase

question
Innoculated 1% tryptone broth is treated with Kovacs' reagent. ;A red layer forms. The organism is Indole ____
answer
Indole positive +
question

;

Innoculated 1% tryptone broth is treated with Kovacs' reagent. ;No color appears after 15 minutes. The organism is ____?

;

answer
Indole Negative -;
question
Kovacs' reagent turns red in the prescence of ______?
answer
Indole
question
These tests are used to identify intestinal bacteria in the colon.
answer

IMViC

  • Indole (Tryptophanase)
  • Methyl Red;
  • Voges-Proskauer (Butanediol Dehydrogenase)
  • Citrate Utilization (Citrase)

question
These tests use MR-VP medium (containing dextrose/glucose)
answer

Methyl Red (MR)

;

and;

;

Voges-Proskauer (VP)

question
Methyl red indicator added to innoculated MR-VP turned the tube red. ;The organism is _____ and the product is ______.
answer

Dextrose positive +

;

Acid

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Methyl red indicator turns red in _____.
answer
Acid
question

;

Methyl red indicator turns yellow/orange in _____.

;

answer
Non-acid
question

;

Innoculated MR-VP turns yellow/orange after 15 minutes. ;The organism is _____.

;

answer
Dextrose negative -
question

Barritt's solutions include what?

;

In what test is it used?

answer

1. alphanaphthol

2. potassium hydroxide (KOH)

;

Voges-Proskauer (VP)

question
Barritt's solutions are added to innoculated MR-VP medium. ;It turns pink/orange/red. ;The organism is ______ and the product is _______.
answer

Butanediol positive +

;

Acetyl methyl carbionl (Acetoin)

question

;

Barritt's solutions are added to innoculated MR-VP medium. ;After 30 minutes, it does not turn pink/orange/red. ;The organism is ______.

;

answer
Butanediol negative -
question
What is the difference between the MR and VP test?
answer

MR test identifies organisims that make strong acids

VP test identifies organisims that make weak acids

;

(The weak acids are more neutral, but still acidic)

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"MR. Strong, meet VP weak"

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With Bromthymol pH indicator, the color green means what?
answer

pH ; 7.6

"pH is less than 7.6"

;

Products range from neutral to acidic

question

With Bromthymol pH indicator, the color blue means what?

answer

pH ; 7.6

"pH is greater than 7.6"

;

The products range from neutral to basic/alkaline

question

Innoculated Simmons Citrate Agar slant turned blue. ;

1) The organisim is citrate _____.

2) The organism contains what enzyme?

answer

1) Citrate positive

2) Citrase

;

(Lots of coliforms (bacteria that grow in the colon) produce a lot of alkaline products. ;Bromthymol indicator turns blue in presence of alkaline products.)

question

;

Innoculated Simmons Citrate Agar slant turned green. ;

1) The organisim is citrate _____.

2) The organism contains what enzyme?

;

answer

1) Citrate negative

2) Trick question: it does NOT contain Citrase

;

(Citrate negative organisms will not grow in the medium)

question
What would be a more correct word for catalase and why?
answer

"Dehydrogenperoxidease"

;

It breaks down hydrogen peroxide (de-) and is an enzyme (-ase)

question
Hydrogen peroxide is poured over an innoculated agar plate. ;Bubbles form. ;The organism is _______. ;The bubbles are made of what?
answer

Hydrogen peroxide or Catalase positive +

;

Bubbles are Oxygen (O2)

question

Hydrogen peroxide is poured over an innoculated agar plate. ;No bubbles form. ;The organism is _______. ;

answer

Hydrogen peroxide or catalase negative -

;

question
Catalase breaks down hydrogen peroxide (H2O2) into O2 and what other product?
answer
Water H2O
question
After a gram stain, the bacteria are blue. ;Is the organisim gram + or gram -?
answer
Gram +
question

After a gram stain, the bacteria are red. ;Is the organisim gram + or gram -?

answer
Gram -
question
List the four stains used in the Gram Stain procedure
answer

  1. Gram's Crystal Violet (Primary Stain)
  2. Gram's Iodine (Mordant)
  3. Ethyl Alcohol (Decolorizer)
  4. Gram's Safranin (Counterstain)

question
A gram + bacteria will ______ the primary stain and ______ the counter (secondary) stain.
answer

Retain the primary

Lose the secondary

;

(Gram + bacteria are blue/violet due to Gram's crystal violet

question

A gram - bacteria will ______ the primary stain and ______ the counter (secondary) stain.

answer

Lose the primary stain

Retain the counter/secondary stain

;

(Gram - bacteria are red because they retain the Safranin counter stain)

question
Two tubes containing MR-VP medium are red. ;What traits does the organism possess? ;
answer
The organism is positive for dextrose + and positive for butanediol +. ;It makes both strong and weak acids.
question

Litmus is red in _____

Litmus is blue in ____

answer

Litmus is red in acids

Litmus is blue in bases

question
Innoculated litmus milk turned pink. ;Interpret this result.
answer

The organism contains lactase which broke down (fermented) the lactose and made acids.

The organism is lactose positive +

question

;

Innoculated litmus milk turned blue. ;Interpret this result.

;

answer

The organism does not contain lactase so the lactose was not fermented

The organism is lactose negative -

question

;

Innoculated litmus milk turned clear/yellow. ;Interpret this result.

;

answer

The organism contains casein hydrolase which broke down the casein protein in the milk.

The organism is casein +

question

;

Innoculated litmus milk turned white. ;Interpret this result.

;

answer

The organism has reduced the litmus. ;The white is the milk.

Organism is Casein negative -

question

;

Innoculated litmus milk turned pink with a solid precipitate (curd) in the tube. ;Interpret the result.

;

answer
The organism is lactose + and fermented the lactose into acids. ;The acids reacted with the casein to form a precipitate--the hard curd.
question

 

 

Innoculated litmus milk turned pink with a solid precipitate (curd) in the tube.  Since the organism is lactose +, the acids reacted with what to form the precipitate?

 

 

answer
Casein (protein)
question

 

 

Innoculated litmus milk turned blue with a solid precipitate (curd) in the tube.  Since the organism is lactose -, what reacted with casein to form the precipitate?

 

 

answer
Rennin (a protein) reacted with Casein (another protein) to form the soft curd.
question
Mr. Maxin's agar supplier sent Mr. Maxin contaminated blood agar dishes. ;The (presumed) bacteria formed a clear area in the blood. ;This clear area was formed by _______, and in this case is an ____-enzyme.
answer

Hemolysin

;

exo-enzyme

question

A supplier sent Mr. Maxin contaminated blood agar dishes. ;The (presumed) bacteria formed a clear area in the blood. ;The organism is hemolytic (hemoglobin) positive or negative? ;Is the organism alpha or beta?

answer

Hemolytic +

Beta Hemolytic

question

;

A supplier sent Mr. Maxin contaminated blood agar dishes. ;The (presumed) bacteria formed a green area in the blood. ;The organism is hemolytic positive or negative? ;Is the organism alpha or beta?

;

answer
Alpha hemolytic positive +
question
A clear area forms around penicillin;filter paper on a lawn streak agar plate. ;The area is called ______ and the organism is ________ to penicillin.
answer

;the Zone of inhibition

;

Sensitive

question
No zone of inhibition forms around bacitracin filter paper on a lawn streaked blood agar plate. ;The organism is sensitive or resistant to bacitracin?
answer
Resistant
question
In this test, one looks for a zone of inhibition.
answer
Beyer Kirby Filter Paper Test
question
Iodine reagent is used in what test?
answer
Starch
question

Nessler's reagent is used in what test?

 

What is Nessler's reagen?

answer

Nitrite Reductase

;

HCl

question
Kovacs' reagent is used in what test?
answer
Indole
question
Barritt's reagent is used in what test?
answer
Voges Proskauer
question

Alphanaphthol and Potassium Hydroxide (KOH) are chemicals of what solution?

;

answer
Barritt's Solutions
question
What are the reagents for the Nitrate reductase test?
answer

Sulfanilic acid 

and

Dimethylalphanaphthylamine

question
Which pH indicator is used in the Urease test?
answer
Phenol red
question
Which pH indicator is used in the Carbohydrate fermentation tests?
answer
Phenol red
question
Which pH indicator is used in the MR test?
answer
Methyl Red indicator
question
Which pH indicator is used in the Citrase test?
answer
Bromthymol blue
question
Which pH indicator is used in the Litmus Milk Reactions?
answer
Litmus
question
What is the substrate in the MR test?
answer
Dextrose
question
What is the product in the MR test?
answer
Acid
question
What is the substrate in the VP test?
answer
Butanediol
question
What is the product in the VP test?
answer
Acetyl methyl carbinol
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