In nitrate reduction, nitrite is an intermediate; which molecule corresponds to nitrite?

In nitrate reduction, nitrite is an intermediate; which molecule corresponds to nitrite?

• A. Nitrate
• B. Ammonia
• C. Nitrite
• D. Nitrous oxide

Answer: (C)

Nitrite is the NO2- form that appears as the intermediate in nitrate reduction. In this pathway, nitrate (NO3-) is reduced by enzymes such as nitrate reductase to nitrite (NO2-), which can then be further reduced to other species like nitric oxide, nitrous oxide, or ammonium, depending on the organism and pathway. The other options correspond to different nitrogen species: nitrate is the oxidized form NO3-, ammonia is NH3/NH4+, and nitrous oxide is N2O. So the molecule that corresponds to nitrite is nitrite, NO2-.

Nitrite is the NO2- form that appears as the intermediate in nitrate reduction. In this pathway, nitrate (NO3-) is reduced by enzymes such as nitrate reductase to nitrite (NO2-), which can then be further reduced to other species like nitric oxide, nitrous oxide, or ammonium, depending on the organism and pathway. The other options correspond to different nitrogen species: nitrate is the oxidized form NO3-, ammonia is NH3/NH4+, and nitrous oxide is N2O. So the molecule that corresponds to nitrite is nitrite, NO2-.