Micro lab final Flashcards
What is the reagent that serves as the substrate in the catalase test?
Hydrogen peroxide
What type of metabolism is associated with catalase production?
Aerobic respiration
For what product is one testing when using the catalase test?
Water and gas
Would you expect anaerobes to produce catalase?
No, they don’t produce hydrogen peroxide as a by product of respiration so they don’t need an enzyme to break it down.
What does a positive or negative catalase test indicate about the metabolism of the cells tested?
\+ = aerobes - = anaerobes
If your catalase test was positive, to what 2 genera could the microorganism belong?
Micrococcus, Staphylococcus
What is the equation catalyzed by the enzyme catalase?
2H202 –> 2H2O + O2
Would you expect your cells to produce catalase?
Yes, our cells are aerobic
What is the function of cytochrome oxidase?
Catalyzes the oxidation of a cytochrome and the subsequent reduction of molecular oxygen either to H2O or H2O2. Aerobes, facultative anaerobes, and microaerophiles
Why are strict aerobes oxidase positive?
oxidase enzymes function in aerobic electron transport systems, organisms that use oxygen can be identified using the oxidase enzyme activity
The oxidase test is used to differentiate among which groups of bacteria?
Neisseria and Moraxella (oxidase +) from Acinetobacter (oxidase -)
Pseudomonads and Vibrionaceae (oxidase +) from Enterobacteriacae (oxidase -)
What is the function of the test reagent in this procedure?
Tetramethyl-p-phenylendiamin dihydrochlorine can be used to test an organisms ability to produce cytochrome oxidase; serves as an artificial substrate to be oxidized by cytochrome oxidase in the presence of oxygen.
