Micro. Phase 2 Flashcards
(45 cards)
For which experiment in the field of virology is Wendell Stanley known?
the crystallization of the tobacco mosaic virus
What is a T-even phage?
The T-phages are a group of 7 bacteriophages that infect e-Coli.
The T-even phages are the even numbered ones: T2,T4 etc.
Which wavelength from within the electromagnetic spectrum contains ultraviolet rays that are used in lamps to sterilize surfaces?
260 μm
UV spectrum = 100-400
What is the mechanism of action of vancomycin?
What other antibiotic has the same MOA?
Inhibits cell wall synthesis.
Cephalothin
What is the MOA of erythromycin and neomycin?
Inhibits protein synthesis
What is the MOA of sulfonamides?
Inhibits protein synthesis.
What is the MOA of chloramphenicol?
Inhibits protein synthesis.
What is another name for protein synthesis?
Translation
At what temp are vegetative bacteria cells killed?
At what temp are viable bacterial endospores killed?
Vegetative: 70C
Endospores: 100C
Which substances kill microorganisms by replacing the hydrogen of the carboxyl, sulfhydryl, or amino groups?
aldehydes
Aldehydes form covalent bonds with protein functional groups.
Which agent inhibits the replication of bacterial DNA by inducing the formation of thymine dimers?
UV light
Ultraviolet nonionizing radiation damages DNA by forming thymine dimer when adjacent thymine bases form bonds together.
When treating a wound, which compound would be most effective to prevent infection? a. 30% alcohol
- chlorine
- Tincture of iodine
- Formaldehyde
Tincture of iodine
Iodine tincture is one of the most effective antiseptics against all bacteria, many endospores, and many viruses.
What is the causative agent of gum lesions caused by bacterial periodontal disease?
Porphyromonas
An individual with food intoxication exhibits double vision, difficulty in swallowing, dizziness, and muscle paralysis. Which organism caused this condition?
Clostridium
What type of bacteria causes Toxic Shock Syndrome?
Toxic shock syndrome results from staphylococcal infection.
In microscopy, which is an advantage of using violet-blue light (420 nm) rather than red light (680 nm)?
Violet light improves resolution. - the shorter the wave length, the better the resolution.
Which strains of Corynebacterium diphtheriae synthesize diphtheria toxin?
strains lysogenic for corynephage
The diphtheria toxin is produced when the bacteria are infected by lysogenic phage carrying the tox gene.
What is the infectious agent of CSD (cat scratch disease)?
Bartonella henselae
What is the MOA of rifamycin?
Inhibits bacterial RNA synthesis.
During the polymerase chain reaction (PCR) process, the incubation mixture is made to cycle between low and high temperatures many times. What is the purpose of the high temperature?
to denature template DNA
Heating converts the double-stranded DNA to single-stranded DNA. Cooling allows the primers to attach to the single strands.
Which ingredient makes mannitol salt agar a selective medium?
Sodium Chloride
Sodium chloride is a salt that inhibits non-Staph. aureus growth.
Folic acid functions as a coenzyme for which process?
Synthesis of purines
How do temperatures above the maximum growth temperature for a bacterial species generally inhibit growth?
by denaturing enzymes
Excessive heat denatures protein. Enzymes are proteins.
When a competitive inhibitor binds to a particular enzyme, how can the reaction rate be increased?
by increasing substrate concentration
Increasing substrate concentration increases the reaction rate, because the enzyme has more noninhibited substrate active sites to react with
