Exam 2 Flashcards

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0
Q

Lipid envelope is much more sensitive to….

A

Disinfectants

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1
Q

Which of the following would not sterilize;

Ionizing radiation, ethylene oxide, alcohol, autoclave, all of the above?

A

Alcohol

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2
Q

Cell wall inhibiting antibiotics block the synthesis of new cell wall formation such that growing bacteria will not complete the walls. Based on this idea at what point in the bacterial growth curve are the bacteria the most vulnerable to these bacteria antibiotics? Lead phase, lag phase, log phase, stationary phase decline phase

A

Log phase

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3
Q

An organism that expends energy to grow in a habitat with low water activity and high solute activity in order to maintain internal solute concentrations to retain water is: acidophile, neutrophile, osmotolerant, aerotolerant anaerobe, pyscroophile.

A

Osmotolerant

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4
Q

Sweetly and salty foods wouldn’t require refrigeration to prevent spoilage because they are ___________?
A. Insufficient nutrients B. Low ph C. Low water activity D. Toxic alkaline Chemicals E. Naturally occurring antibiotics

A

C. low water activity

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5
Q

A(n) _________ is used to prevent infection by killing or inhibiting pathogen growth on animal tissues.

A

Antiseptic

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6
Q

Which of the following does not apply to phenols?
A. It is the standard disinfectant against which others are evaluated (ie phenol coefficient).
B. It’s activity is not reduced in the presence of organic matter.
C. It has a sweet smell and no detrimental effects on the skin.
D. It acts by disrupting membranes and denaturing proteins.

A

C. It is a sweet….

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7
Q
Which of the following has it beta-lactam ring?
Macrolide
Tetracyclines
Quinolones
Aminoglycosides
Penicillins
A

Penicillins

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8
Q
This antibiotic does not target the linking of Peptidoglycan subunits into the growing cell wall but inhibits a different part of cell wall synthesis pathway.
Bacitracin 
Ampicillin .P.
Vancomycin .N.
Methicillin .P.
Ciprofloxin (cephelasporin)
A

Bacitracin

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9
Q

In general when using chemical disinfectants to inactivate viruses or limit their transmission
A. Naked viruses are more tolerant to chemical disinfectants. Yes
B. Envelope viruses are more tolerant to chemical disinfectants. No
C. Naked viruses and envelope viruses are equal in their tolerance to disinfectants

A

A

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10
Q
Bacteria that grow at the surface in bodies of water would be considered...
An aerobe 
Aerotolerant
An obligate anaerobe
Capnophiles
An alkalophic
A

An aerobe

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11
Q

Gram-negative organisms are often _______ to chemical disinfectants then gram-positive organisms due to the presence of an outer membrane Porins and LPS.

A

Less susceptible

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12
Q
Both zanamivir and islet amicus are neuramidase inhibitors which block the function of influenzae protein neuramidase. These drugs would...
Prevent viral attachment
Blocking viral penetration
Blocking viral polymerase
Slowing viral release
Causing mutations in viral genome
A

Slowing viral release

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13
Q

Heavy metals generally kill microorganisms by…
Uniting with water molecules and dehydrating the microorganism.
Reacting with sulfhydryl groups of proteins and binding them together.
Penetrating the lipids microbial cytoplasm
Inhibiting flagellar motion in the microorganism

A

Reacting with Sulfhydryl groups of proteins and binding them together

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14
Q
The chemical Counterpart of the autoclave uses...
A. Mercury oxide in a closed chamber
B. Iodine in an iodophor solution 
C. Phenol in the form of cresol
D. Ethylene oxide with an inert gas
A

Look up answer

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15
Q
Sulfanilimide works by competitive inhibition and blocks...
A. The effects of B-lactam antibiotics
B. tRNA entry into the ribosome
C. Mycotic acid synthesis
D. Formation go frolic acid
A

B.

16
Q

Beta lactam antibiotics function by…
A. Blocking the translocation of the ribosome along the mRNA
B. Interacting with RNA polymerase and inhibiting transcription initiation
C. Blocking the transport of peptidoglycan across the cell membrane.
D. Blocking the function of topoisomerase
E. Interacting with transpeptidases, inhibiting the cross-linking of cell wall

A

E.

17
Q

Isoniazid is of particular value…
A. For determining the MIC of a drug
B. For performing the Kirby Bauer test
C. For separating gram-positive and gram-negative bacteria
D. For treating tuberculosis caused by mycobacteria

A

D.

18
Q

If you were cleaning benches or tables on which you would be placing patients with exposed skin you would probably want to use a disinfectant such as _________.

A

Alcohol

19
Q

Which of the following disinfectants should be used if high concentrations of organic matter are present around the contamination.
Alcohols halogens phenols or heavy metals

A

Phenols

20
Q

During the anthrax scare the Postal Service needed a good means to sterilize mail without harming it. In order to do this they needed a chemical that they can easily penetrate through the seems of an envelope and is capable of destroying spores (ie sterilization) which of the following chemicals might be a good candidate.
Phenol’s heavy metals isopropanol ethylene oxide UV radiation

A

Ethylene oxide

21
Q

Which of the following would kill the greatest percentage of cells?
A D100 value of 10 minutes
A D100 value of 5 minutes
Both would kill the same percentage of cells

A

Both would kill the same percentage of cells

22
Q

Which of the following chemical disinfectants would not disrupt cell membranes…
Cationic detergents, phenolic compounds, 70% alcohol, heavy metals, all of these disrupt membranes

A

Heavy metals

23
Q

Some antiviral drugs block pH dependent entry mechanisms used by viruses, which viruses would most likely be impacted by this drug?
Naked viruses, envelope viruses, bacteriophages, plant viruses

A

Envelope viruses

24
Q

After examining the equation for growth/killing N=No e ^ uT, which value will ultimately have the greatest impact on the final number of bacteria?
The initial bacterial load, the growth/death rate constant, e

A

The growth/death rate constant

25
Q

You’re watching television and the drug commercial for genital herpes is on. You tell your friend that this drug is a nucleoside analog. Your friend asks if nucleotides are important for our genetics, then why aren’t our cells affected by this drug? What do you tell him?
Viruses use different nucleotides in our genomes than we do.
Viruses have single-stranded genomes and we have double-stranded.
Viruses are continually synthesizing genome and transcripts at a higher rate than us.
All viruses use a different DNA polymerase than we do.
None of the above.

A

Viruses are continually synthesizing genome and transcripts at a higher rate than us

26
Q

Microbial resistance to heaving metals is similar to resistance to tetracyclines in that
Both are done by modifying the target.
Both are done by modifying the antimicrobial.
Both are done by efflux pumps.
Both are due to mutations.

A

Both are done by efflux pumps

27
Q

The term facultative anaerobic refers to the microorganism that…
Doesn’t use oxygen but tolerates it.
Is killed by oxygen.
Uses oxygen when it is present or grows without oxygen when it is absent.
Requires less oxygen than is present in the air.

A

Uses oxygen when is present or grows without oxygen when it is absent

28
Q

The most selective antibiotics, i.e. Best selective toxicity, are those that interfere with the synthesis of…
DNA, RNA, cell walls, plasma membrane, Pili

A

Cell walls

29
Q

Many young adults get “walking pneumonia” which is caused by pleomorphic bacteria Mycoplasma pneumonia. Based on your knowledge of the mycoplasmas, which of the following drugs would not be affected against this infection.
Tetracycline, riflamycin, erythromycin, sulfonamide, ampicillin

A

Ampicillin

30
Q

You prepare test tubes containing solid agar media. The concentration of oxygen at the surface of the agar media is normal, but gradually decreases to zero at the bottom of the test tube. You inoculate two test tubes by stabbing an inoculating needle through the agar all the way to the bottom of the tube. You incubate the two test tubes overnight and examine them the next day. Upon observation, test tube 1 shows growth only at the surface While tube two shows growth throughout the entire tube. Based on this we can conclude that test tube one was inoculated with a_______ and test tube to what was inoculated with a _______.
A. Osmophile; xerophile
B. Facultative anaerobe; obligate anaerobic
C. Microaerophile; obligate aerobic
D. Obligate aerobe; facultative anaerobe
E. Xerophile; halophile

A

D

31
Q

Cephalosporins resemble which anabiotic in the mode of action due to a common core structure?
Penicillin, tetracycline, Polymyxin, macrolides such as erythromycin, vancomycin

A

Penicillin

32
Q

Cold sterilization refers to the use of…

Autoclave, UV radiation, ionizing radiation, alkylating agents, lypohilization

A

Find answer

33
Q

Heat sensitive materials, electronics, cloth, and bulky material such as mattresses should be sterilized using….
Ethylene oxide, autoclave, UV radiation, pasteurization, phenolic sprays.

A

Ethylene oxide

34
Q

Quaternary ammonium compounds, quarts, are a type of…

Alkylating agent, detergent, phenolic substance, heavy-metal

A

Find answer

35
Q

You isolate the following enzymes from an unknown organism, superoxide dismutase and catalase. You can conclude that this organism is…
Aerobic, and aerotolerant anaerobe, an obligate anaerobe, an acidophile, an alkalophile

A

Find answer

36
Q

Your asked to grow the organism Sulfalobus acidocaldarius. Which of the following would be important to grow this organism.
A. An incubator capable of temperature near 100°C.
B. Media with high molar concentrations of salt.
C. A media with high pH.
D. A media with low pH.
E. A refrigerator for low incubation temperature.

A

D