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MOD-Exam 3 > Bacteria: Introduction > Flashcards

Bacteria: Introduction Flashcards

1
Q

Which of the following correctly describes bacteria?

A. Eukaryotes with cell membrane bound nuclear material

B. Prokaryotes with cell membrane bound nuclear material

C. Eukaryotes with nuclear matieral that is not membrane bound

D. Prokaryotes with nuclear material that is not membrane bound

E. Archea with nuclear material that can be membrane bound

A

D. Prokaryotes with nuclear material that is not membrane bound

Not 100% accurate, but a quick generalization.

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2
Q

Which of the following steps is the first step in gram staining?

A. Pour safranin and wait 30 seconds and wash under water

B. Pour on crystal violet stain and wait 60 seconds

C. Rinse with water and flood with iodine and wait 60 seconds

D. Rinse with water and decolorize using 95% alcohol

A

Pour on crystal violet stain and wait 60 seconds

NOTE:

Steps of grieving: First your sad and blue (crystal violet) and then you end up angry and red (safranin)

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3
Q

Which of the following is used to decolorize the slide when performing gram staining?

A. Crystal violet

B. Iodine

C. 95% alcohol

D. Safranin

E. Water

A

95% alcohol

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4
Q

T/F: For any stain you must first smear the sample on a slide, and freeze the slide in order for the bacterium to adhere

A

False;

You must heat the slide in order to adhere the bacterium to the slide

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5
Q

What color do gram positive bacteria stain?

What color do gram negative bacteria stain?

A

What color do gram positive bacteria stain?

Blue

What color do gram negative bacteria stain?

Red

Red heads were seen as a negative omen

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6
Q

Penicillin binds and deactivates which of the following enzymes found in the bacteria’s inner cytoplasmic membrane which catalyzes cross-linking of its AAs?

A. Transpeptidase

B. Cispeptidase

C. Bipeptidase

D. All of the above

A

Transpeptidase

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7
Q

Unlike animals, which of the following is not found spanning the cytoplasmic membrane layers in bacterium?

A. Peptidoglycan

B. LPS

C. Cholesterol and other sterols

D. All of the above

A

Cholesterol and other sterols

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8
Q

Gram negative vs. Gram positive bacteria:

Which has a thicker outer layer with more complex cross linking and a higher [] of peptidoglycan (60-100%)?

Which has an envelope made up of 3 layers (instead of 2) and contains a periplasmic space, endotoxins (lipid-A), and porin channels?

Which is resistant to lysozyme and penicillin attack?

A

Which has a thicker outer layer with more complex cross linking and a higher [] of peptidoglycan (60-100%)?

Gram positive

Which has an envelope made up of 3 layers (instead of 2) and contains a periplasmic space, endotoxins (lipid-A), and porin channels?

Gram negative

Which is resistant to lysozyme and penicillin attack?

Gram negative

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9
Q

Which of the following is an important polysaccharide that can be used as antigenic determinant for serologic identification of gram positive bacteria?

A. Murein lipoprotein

B. Lipid A

C. Lipopolysaccharide (LPS)

D. Teichoic acid

A

Teichoic acid

NOTE: Lipid A and LPS are the same thing and are found in gram negative bacteria’s outer membrane (layer 3)

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10
Q

The thin peptidoglycan layer of gram negative bacteria contains what helical lipoprotein that binds layer 2 to the unique outer membrane (layer 3)?

A. Murein lipoprotein

B. Lipid A

C. Lipopolysaccharide (LPS)

D. Teichoic acid

A

Murein lipoprotein

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11
Q

Periplastic space filled with a gel containing enzymes and proteins is found in which of the following locations?

A. 2nd and 3rd layer of gram negative bacteria

B. 1st and 2nd layer of gram negative bacteria

C. 1st and 2nd layer of gram positive bacteria

D. 2nd and 3rd layer of gram positive bacteria

A

B. 1st and 2nd layer of gram negative bacteria

NOTE:

gram positive bacteria don’t have a 3rd layer

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12
Q

T/F: Gram positive cells have a high lipid content compared to gram negative cells

A

False

Flip it and reverse it

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13
Q

What is the name of the endotoxin that gets released from lysed gram negative bacteria and once in our circulation can cause fever, diarrhea, and potentially endotoxic (spetic) shock?

A

Lipopolysaccharide (LPS) aka Lipid A

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14
Q

Which of the following correctly describes why gram negative bacteria do not stain blue?

A. Gram negative outer layer cannot absorb crystal violet stain

B. Gram negative outer layer more readily absorbs safranin than compared to crystal violet

C. Alcohol partially dissolves the lipids that comprise much of the gram negative’s outer layer, and thus washes away the crystal blue stain with it

D. Iodine partially dissolves the lipids that comprise much of the gram negative’s outer layer, and thus washes away the crystal blue stain with it

A

C. Alcohol partially dissolves the lipids that comprise much of the gram negative’s outer layer, and thus washes away the crystal blue stain with it

Longer explanation:

Alcohol partially dissolves lipids, which are more highly concentrated in gram negative outer layer vs. gram positive. This gets rid of much of the 3rd outer layer and the blue stain that was trapped within it. Now the introduction of the counterstain Safranin (red) has room to bind.

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15
Q

Look at this one

A

Look at this one

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16
Q

What are the 6 classic gram positive bacteria that contribute to human disease?

Which 2 are cocci, and of the 2 which one forms clusters?

Of the 4 rod shapped (bacilli), which 2 produce spores?

A

What are the 6 classic gram positive bacteria that contribute to human disease?

Streptococcus, Staphylococcus, Bacillus (Anthracus), Clostridium, Corynebacterium, Listeria

Which 2 are cocci, and of the 2 which one forms clusters?

Streptococcus and Staphylococcus (cluster)

Of the 4 rod shapped (bacilli), which 2 produce spores?

Bacillus (Anthracus) and Clostridium

  • NOTE:*
  • i’m positive Some Say Basic Clowns are Corny Losers*
  • This mneumonic puts the gram positive bacteria so that :*
    • the first 2 are cocci with #1 forming strips (like a 1) and #2 forming cluster*
    • the #3-6 are rod shaped with #3&4 spore forming, and #5&6 j-chillin*
17
Q

Treponema Pallidum is a gram negative bacterium that causes syphilis and has what morphology?

A. Cocci

B. Spiral

C. Rod shaped

D. Pleimorphic

A

Spiral

NOTE: It is a Spirochetes

18
Q

Which of the following categorical exceptions is described as weakly gram negative, can only be seen with a darkfield microscope, has an additional outer wall, and periplastic flagella?

A. Spirochetes

B. Mycobacterium

C. Mycoplasm

D. None of the above

A

Spirochetes

19
Q

Which of the following categorical exceptions is weakly gram positive and stains better with an acid-fast stain?

A. Spirochetes

B. Mycobacterium

C. Mycoplasm

D. None of the above

A

Mycobacterium

20
Q

Which of the following categorical exceptions has a single cell membrane instead of a cell wall, and is neither gram negative or gram positive?

A. Spirochetes

B. Mycobacterium

C. Mycoplasm

D. None of the above

A

Mycoplasm

21
Q

What are the 2 cocci, which are technically diplocci, that are gram negative bacteria?

A

Neisseria

Moraxella

Neisseria and Moraxella sound like the names of 2 evil witches

22
Q

Which of the following are gram POSITIVE cocci?

A. Moraxella and Streptococcus

B. Morexella and Neisseria

C. Streptococus and Neisseria

D. Streptococus and Staphylococcus

A

Streptococus and Staphylococcus

23
Q

To avoid the toxic affects of reactive oxygen, bacteria utilize which of the following enzymes to breakdown 2H2O2 –> 2H2O + O2?

A. Catalase

B. Oxidase

C. Superoxide Dimutase

D. None of the above

A

Catalase

24
Q

Obligate aerobes are bacteria that utilize glycolusis, TCA and ETC, and must have oxygen to grow. What are the 2 common Obligate aerobes?

Gram-negative:

Acid fast:

A

Neisseria

Mycobacterium

25
Q

Faculative anaerobes are aerobic bacteria that can still grow without oxygen by switching to fermentation process. What are some common Faculative anaerobes?

Gram-positive (4):

No cell wall:

A

Staphylococcus, Bacillus anthracis, Corynebacterium and Listeria

i’m positive that the Faculative anaerobes are the Same Basic Corny Losers

Mycoplasm

26
Q

Microaerobic bacteria are mostly anaerobic and utilize fermentation as a means of energy, however they can tolerate low O2 environments. What common gram positive and gram negative bacteria are microaerophilic?

A

Streptococcus

Spirochetes

27
Q

What common gram positive bacteria hates oxygen because it has no enzymes to defend against oxygen?

A. Streptoccocus

B. Staphylococcus

C. Clostridium

D. Corynebacterium

A

Clostridium

28
Q

Why is the catalase reaction an easy way to differentiate between Streptococcus and Staphylococcus?

A. Strep is a faculative anaerobe and contains enzymes that work to defend it from toxic metabolites of O2 via the catalase reaction

B. Staph is a faculative anaerobe and contains enzymes that work to defend it from toxic metabolites of O2 via catalse reaction

C. Strep is a microaerophilic bacterium that has no catalase to carry-out the catalase reaction, and only has superoxide dimutase

D. B and C

A

D.

B. Staph is a faculative anaerobe and contains enzymes that work to defend it from toxic metabolites of O2 via catalse reaction

C. Strep is a microaerophilic bacterium that has no catalase to carry-out the catalase reaction, and only has superoxide dimutase

NOTE:

Staphylococcus has an A in it like Catalase, but Strep does not

29
Q

T/F: Never give anti-biotics before giving a culture

A

True

30
Q

Endospores are a metabolically dormant for of bacteria that allow it to become resistant to heat, cold, drying, and chemical agents. Endospores are only formed by 2 genera of bacteria which both happen to be gram-positive. What are those 2 genera? Specify which one is areobic and which is anaerobic?

A
  • aerobic* Bacillus
  • anaerobic* Clostridium

NOTE:

You can find endospores in the Back of your Closet

31
Q

Which of the following BEST describes and endotoxin?

A. a protein that gets released in food as the bacterium grows and can cause food posioning

B. a protein that gets released when the bacterium is lysed

C. A substance/molecule that is shed off from the outermembrane often during lysis

D. All of the above are correct

E. All but B are correct

A

A substance/molecule that is shed off from the outermembrane often during lysis

32
Q

T/F: Endotoxins that have been found to cause disease in humans have only been attributed to gram-negative bacteria thus far

A

True

33
Q

The most major endogenous mediator of shock is what?

A. TGF-B

B. TGF-a

C. TNF

D. IL-6

A

TNF

34
Q

Enterotoxins, a type of exotoxin, generally works on the GI through which of the following ways?

A. Inhibiting NaCl reabsorption and NaCl secretion

B. Activating NaCl reabsorption and inhibting NaCl secretion

C. Inhibiting NaCl reabsorption and Activating NaCl Secretion

D. Activating NaCl reabsorption and NaCl secretion

A

C. Inhibiting NaCl reabsorption and Activating NaCl Secretion

35
Q

Which of the following involves a bacteriophage that carries bacterial DNA to other bacterium, and associated with immunity against lysing?

A. Transformation

B. Transduction

C. Conjugation

D. Transposons

A

Transduction

36
Q

Which of the following ,echanisms of bacterial genetics contributes most to the rapid spread of antibiotic resistance in bacteria?

A. Transformation

B. Transduction

C. Conjugation

D. Transposons

A

Transposons

NOTE: Transposons are mobile genetic elements that can be inserted in dna without being homologous, and get replicated by utilizing the host’s DNA transcriptions to replicate

37
Q

Transformation is the passage of DNA fragments, which are released from the lysed bacteria, to tthe cell wall of another bacteria where it is absorbed and accepted by the local bacterium if which of the following is true?

A. There is high relation or homology between DNA of the donor and acceptor bacterium

B. There is low relation or a lack of homology between DNA of the donor and acceptor bacterium

C. The sex pillus transfering the DNA or F plasmid (circular dsDNA) is in direct contact with the acceptor bacterium

D. All of the above are true

A

A. There is high relation or homology between DNA of the donor and acceptor bacterium

NOTE: Option C is describing Conjugation

MOD-Exam 3 (6 decks)

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