Why is the catalytic activity of enzymes essential to ensure and regulate cellular metabolism?
All biochemical reactions that occur in living cells are
... [Show More] regulated by enzymes.
___________ is a biooxidative process that occurs aerobically, with molecular oxygen serving as the final electron acceptor, or anaerobically, with an inorganic ion acting as a final electron acceptor. _____________is a biooxidation that utilizes an organic compound as the final electron acceptor.
Cellular Respiration; Fermentation
All microorganisms use pyruvic acid in the same way.
False
What is the purpose of the Triple Sugar-Iron test?
The TSI test is designed for the rapid separation and presumptive identification of enteric organisms.
The Triple sugar-iron medium contains a lower concentration of glucose than of lactose and sucrose to allow for detection of the utlization of this substrate only.
True
Explain the purpose of the phenol red in the TSI medium.
To detect carbohydrate fermentation caused by the presence of acidic end products.
Explain the purpose of thiosulfate in the TSI medium.
It serves as a substrate for hydrogen sulfide production.
The IMViC series of tests are medically significant because it can be used for the identification of enteric organisms, including both pathogens and nonpathogens.
True
The end products of tryptophan degradation are indole and pyruvic acid. Why do we test for the presence of indole rather than pyruvic acid as the indicator of tryptophanase activity?
Pyruvic acid is a utilizable intracellular metabolite and therefore is not excreted into the medium. Indole is a waste product and can be detected in the medium.
Which of the following substrates are available to cells for H2S production? Select all that apply.
thiosulfates
sulfates
cysteine
sulfites
Regarding how SIM medium is used to detect motility, the growth of a ______________organism would be restricted to the line of inoculation, whereas __________is recognized by growth that is not restricted to the line of inoculation.
nonmotile; motility
Ferrous ammonium sulfate in SIM agar serves as an indicator by combining with the hydrogen sulfide gas to form a detectable, insoluble, black ferrous sulfide precipitate within the medium.
True [Show Less]