Question

Carefully read the following reactions carried out by nitrifying bacteria. Identify the statement about these equations which is not true.
${ 2NH }_{ 3 }+{ 3O }_{ 2 }\rightarrow { 2NO^{ - } }_{ 2 }+{ 2H }^{ + }+{ 2H }_{ 2 }{ O }$-- (I)
${ 2NO }^{ - }_{ 2 }+{ O }_{ 2 }\rightarrow { 2NO }_{ 3 }^{ - }$--- (II)
(a)Step (I) is carried out by Nitrosomonas or nitrosococcus
(b)Step (II) is carried out by Nitrobacter
(c)Both step (I) and step (II) can be called nitrification
(d)Both the steps occur only in photoautotrophs

Answer 1

The process that transforms ammonia to nitrite and then to nitrate is nitrification and is another significant step in the global nitrogen cycle. The bulk of nitrification takes place aerobically and is done exclusively by prokaryotes.

Complete answer:
I) In the first step, through the action of Nitrosomonas and nitrosococcus bacteria, ammonia is oxidized into nitrites.
II) In the second step, with the aid of Nitrobacter and microcystis, nitrate is further oxidized into nitrate.
Both reactions are involved in the nitrification process. Chemoautotrophs are called those nitrifying bacteria involved.
Nitrification is the biological oxidation reaction of ammonia to nitrite and thereby the oxidation of the nitrite to nitrate. The transformation of ammonia to nitrite is the rate-limiting step of this reaction. Nitrification is a big step in the nitrogen cycle in the soil. It is an aerobic process carried out in small groups by autotrophic bacteria and archaea. This was discovered by the Russian microbiologist Sergei Winogradsky.

Additional information:
Photoautotrophs are organisms that, through the photosynthesis process, can produce their own energy using light and carbon dioxide. A combination of autotroph, the word for an organism that produces its own food, and the prefix photo, which means "light," is the word photoautotroph. Essentially, photoautotrophs make their own food, which is how they can live and reproduce. For the survival of heterotrophs, however, they are also necessary, species that can not make their food and must consume other species to survive.

So, the correct answer is ‘both the steps occur only in photoautotrophs’.

Note: Autotrophic bacteria: synthesize their own organic food from inorganic substances Autotrophic bacteria are two types of autotrophic bacteria: I photoautotrophic (photosynthetic) using light energy and (ii) chemoautotrophic (chemosynthetic) using chemical energy.