Your Patient Asks You to Explain How the Urea Breath

Multiple Choice

Your patient asks you to explain how the urea breath test works. You tell her that in the test, she had been asked to swallow urea containing an unusual form of carbon-non-radioactive 13C (an isotope) . After 10-30 minutes, she was asked to breathe into a receptacle, and her breath had been analyzed for the presence of this form of carbon in the carbon dioxide that she exhaled. You explain that the CO2 she exhaled contained 13C, so

A) her test indicates the presence of H. pylori-the organism produces ammoniase that breaks down the 13C-containing urea that the patient swallowed into urea and CO2 containing 13C which could be measured.
B) her test indicates the presence of H. pylori-the organism contains 13C in its cell wall, and in the presence of stomach acid, the cell wall is broken down to release CO2 containing 13C which could be measured.
C) her test indicates the presence of H. pylori-the organism produces urease that breaks down the 13C-containing urea that the patient swallowed into ammonia and CO2 containing 13C which could be measured.
D) her test indicates that her stomach cells used the 13C-containing urea in cellular respiration, producing glucose and releasing CO2 containing 13C as a byproduct.
E) nobody really understands how the urea breath test works, but that it is well known that anybody who drinks urea containing 13C and exhales CO2 containing this element afterwards needs treatment for an ulcer.