MOD II Final Exam Flashcards

1
Q

What color do gram-positive organisms stain?

A

They stain BLUE! Gram-positive = BLUE. I’m positively BLUE over you!!

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2
Q

What color do gram-negative organisms stain?

A

They stain RED! Gram-negative = RED. No (negative) RED commies!

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3
Q

What enzyme cross links the 4 chain amino acid sidechains in the peptidoglycan layer or cell wall?

A

Transpeptidase, located in the inner cytoplasmic membrane, catalyzes this cross linking.

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4
Q

What medication binds to transpeptidase?

A

Penicillin binds to and inhibits this enzyme. Earning transpeptidase the name Penicillin binding protein.

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5
Q

Gram-postive cell wall is thick/thin?

Gram negative cell wall is thick/thin?

A

Gram-positive cell wall is thick.

Gram-negative cell wall is thin.

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6
Q

Do gram-positive cell cellular membranes contain cholesterol or other sterols?

A

No

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7
Q

What is the antigenic determinant in in gram-positive cell walls?

A

Teichoic Acid

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8
Q

What are the layers of the gram-positive membrane?

A

1) Outer cell wall composed of complex cross-linked peptodoglycan, teichoic acid, ploysaccharides, and others
2) Cytoplasmic cell membrane

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9
Q

What are the layers of the gram-negative membrane?

A

1) Outer membrane containing LPS and Porin
2) Petidoglycan Layer (cell wall)
3) Cytoplasmic Membrane

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10
Q

The thing peptidoglycan layer does not have is teichoic acid, what does it have instead?

A

A helical Murein lipoprotein. Originating from the peptidoglycan layer is extends to and binds to unique third outer layer.

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11
Q

What makes the the outer membrane unique?

A

It contains lipopolysaccharide (LPS).

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12
Q

Lipopolysaccharide is composed of what three covalently linked components?

A

1) Outer carbohydrate polysaccharide chains of Oligosaccharides, called the O-specific side chain or O-antigen
2) The center part is water soluble core polysaccharide
3) Inferior to the center part is Lipid A.

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13
Q

What is known as the gram-negative endotoxin?

A

Lipid A. When bacterial cells are lysed by our immune system fragments of their membranes are released into circulation causing fever, diarrhea, and possibly fatal endotoxic septic shock.

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14
Q

Gram-Postive cell traits are:

A
1- 2 layers
2- Low lipid content
3- No endotoxin
4- No periplasmic space
5- No porin channel
6- Vulnerable to lysozyme and penicillin attack
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15
Q

Gram-Negative cell traits are:

A
1- 3 layers
2- High lipid content
3- Endotoxin (LPS) -lipid A
4- Periplasmic space
5- Porin Channel
6- Resistant to lysozyme and penicillin attack
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16
Q

What are four major shapes of bacteria?

A

1-Cocci-spherical
2-Baccilli- rods. short bacilli called coccobacilli
3-Spiral forms- comma-shaped, S-shaped, or spiral shaped
4-Pleomorphic-lacking a consistent shape, like jello

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17
Q

How many gram-positives are cocci and what are they?

A

Three are cocci and they are:

1) Streptococcus
2) Enterococcus–> forms strips of cocci
3) Staphylococcus–>forms clusters of cocci

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18
Q

How many gram-positive are rod-shaped (bacilli) and what are they? Which produce spores?

A
Four are rod-shaped and they are:
               Spore producers:
4)Bacillus (aerobic)
5) Clostridium (anaerobic)
              Non-Spore producers:
6) Corynebacterium
7) Listeria
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19
Q

How many gram-negative are cocci and what are they?

A

Two gram-negative are actually diplococci (kissing coffee beans) and they are:
1) Neisseria
2) Moraxella
A “Neiss”eria donut gives “Mor”axella

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20
Q

How many gram-negative are spiral-shaped and what are they?

A

One group of spiral-shaped organisms and they are:

1)Treponema pallidum–>causes syphilis

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21
Q

Mycobacteria: +/-, staining, and disease?

A
  • weakly gram-positive
  • better with a special stain called acid-fast stain
  • organisms in this group cause tuberculosis and leprosy
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22
Q

Spirochetes: +/-, membrane trait, form of motility?

A
  • gram-negative cell wall
  • spirochetes are surrounded by an additional phospholipid-rich outer membrane with few exposed proteins which helps it evade immune detection (“stealth” all stealthy like organisms)
  • periplasmic flagella, under the outer membrane, that internally rotate propelling the organism forward
23
Q

Mycoplasma: +/-, membrane trait

A
  • neither gram negative or positive
  • do not have a cell wall
  • only have a simple membrane
24
Q

Erythromycin inhbits protein synthesis where?

A

Works at the 50s subunit.

25
Q

Tetracyclin inhibits protein synthesis where?

A

Works are the 30s subunit.

26
Q

What are Obligate Aerobe examples of gram-positive, gram-negative, and acid-fast?

A
-Gram-positive:
              Nocardia, Bacillus Cereus
-Gram-negative:
              Bordetella, Brucella, Legionella, Pseudomonas, Neisseria
-Acid-fast:
               Mycobacterium, Nocardia
27
Q

What are Facultative Anaerobe examples of gram-positive, gram-negative, and no cell wall?

A

-Gram-positive:
Coryne, Lister, Actinomyces, Bacillus Anthracis, Staph. C.L.A.B.S.
-Gram-negative: most other gram-negative rods
-No cell wall: Mycoplasma

28
Q

Examples of Micoaerophilic

A
  • Gram-positive: Streptococcus, Enterococcus, streptococci (some species are falcultative anaerobes
  • Gram-negative: Spirochetes (treponema, borrelia, leptospira), and Campylobacter
29
Q

What are Obligate Aerobes?

A

Need oxygen. Use glycolysis, the Krebs cycle, and the electron transport chain.

30
Q

What are Facultative Anaerobes?

A

These bacteria can use oxygen or fermentation of energy. Have catalase and superoxide dismutase. Can grow without oxygen

31
Q

What are Microaerophilic bacteria?

A

Use fermentation and have no electron transport system.

Can tolerate low amounts of Oxygen because they have superoxide dismutase

32
Q

What are Obligate Anaerobes?

A

Hate oxygen and have no enzymes to defend against it!

33
Q

Examples of obligate anaerobes?

A

-gram-positive-
Clostridium
-gram-negative-
Bacteroides

34
Q

Pleomorphic examples of Gram-negative bacteria?

A

Chlamydia and Rickettsiae
these also do not have the metabolic machinery to utilize oxygen. They are energy parasites, and must steal their host’s ATP directly.

35
Q

What is the Embden-Meyerhof Pathway?

A

This is the pathway of glycolysis that we have studied in biochemistry.

36
Q

What are autotrophs?

A

organisms that use inorganic chemical sources such as ammonium and sulfide

37
Q

What are heterotrophs?

A

Use organic carbon compounds.

38
Q

Chemoheterotrophs

A

Use chemical and organic compounds such as glucose for energy.

39
Q

Fermentation is what?

A

glucose is broken down to pyruvic acid, yielding ATP directly

40
Q

What two organisms form endospores?

A

only 2 genera of bacteria , both of which are gram-positive , form endospores:

  • Bacillus (aerobic)
  • Clostridium (anaerobic)
41
Q

What is a biofilm?

A

extracellular polysaccharide network mechanical scaffold around bacteria.

42
Q

What is the most effective way to cure an infection involving a prosthetic device?

A

Remove the device i.e. catheter, I.V.

43
Q

What are facultative intracellular organisms?

A

organisms that can survive inside the a neutrophil or macrophage after being phagocytosed

44
Q

What are the facultative intracellular organisms?

A
1-Listeria monocytogenes-->LISTen
2-Salmonella typhi-->SALly
3-Yersinia-->YER
4-Francisella Tularensis-->FRiend
5-Brucella-->BRUCE
6-Legionella-->Must
7-Mycobacterium-->LEave
8-Nocardia-->NOw
45
Q

Where is the spirochetes flagella?

A

It runs underneath their unique outer membrane sheath

46
Q

What are pili?

A

Pili are adherence factors AKA adhesins

47
Q

India Ink stain looks like?

A

Not taken up by cell wall so it appears as a clear halo around the cell. I.e. the fungus Cryptococcus.

48
Q

Quellung Reaction looks like?

A

Antibodies bind to the capsule causing it to swell with water.

49
Q

Opsonization is what?

A

Macrophages or neutrophils can bind to the Fc portion of the antibody and gobble up the bacteria

50
Q

Endotoxins pathogenic to humans have only been found in gram + or - bacteria?

A

gram-negative

51
Q

What is the most famous endogenus mediator of sepsis?

A

TNF which is also called a cachectin

52
Q

TNF triggers the release of what?

A

The cytokine IL-1 which causes the release of other cytokines and prostaglandins. The emdiators act on blood vessels and organs to produce vasodilation, hypotension, and organ system dysfunction.

53
Q

The mnemonic cAMP stands for the four bacteria that produce exotoxins that increase levels of cAMP. What does it stand for?

A
c = cholera (Vibrio cholera)
A = anthrax (bacillus anthracis)
M = Montezuma's revenge (popular name for enter0-toxigenic E. coli)
P = pertussis (Bordetella pertussis)