Question

1. Helicobacter pylori, a pathogen of the stomach,produces a powerful urease. Why might urease be a useful enzyme forthis microbe?

2. T/F If two different tests can be done in MRVP medium, youshould add the methyl red (MR) and Voges-Proskauer (V-P) reagentsto the same tube.

3. After incubation, a citrate test for Escherichiacoli is green. What is the best explanation for thisresult?

4.Select the appropriate statements regarding the decarboxylasetests.

Only one type of decarboxylase is present in the medium.
	Sterile mineral oil should be added to prevent artificialalkylation of the media�s surface.
	The test organism is inoculated into the tube by stabbing theagar.
	During the early stages of incubation, the medium will appearyellow; if the targeted decarboxylase is present, the medium willgradually turn purple.
	During the early stages of incubation, the medium will appearpurple; if the targeted decarboxylase is present, the medium willgradually turn yellow.
	The test organism is inoculated into the tube by adding a fewdrops of an isolate.
	Proteins are not present in the test media, it is simplysupplemented with a specified amino acid.