pls explain 2 me wad is carbon cycle, nitrogen cycle, and nitrifying/denitrifying?

Answer 1

about carbon cycle:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CarbonCycle.html

about nitrogen cycle:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/NitrogenCycle.html

Nitrification is the biological oxidation of ammonia with oxygen into nitrite followed by the oxidation of these nitrites into nitrates. Nitrification is an important step in the nitrogen cycle in soil.

The oxidation of ammonia into nitrite, and the subsequent oxidation to nitrate is performed by two different bacteria (nitrifying bacteria). The first step is done by bacteria of (amongst others) the genus Nitrosomonas and Nitrosococcus. The second step (oxidation of nitrite into nitrate) is (mainly) done by bacteria of the genus Nitrobacter. All organisms are autotrophs, which means that they take carbon dioxide as their carbon source for growth.

Nitrification also plays an important role in the removal of nitrogen from municipal wastewater. The conventional removal is nitrification, followed by denitrification. The cost of this process resides mainly in aeration (bringing oxygen in the reactor) and the addition of an extra organic energy source (e.g. methanol) for the denitrification.

Nitrification is a process of nitrogen compound oxidation (effectively, loss of electrons from the nitrogen atom to the oxygen atoms) :

NH3 + O2 → NO2− + 3H+ + 2e−
NO2− + H2O → NO3− + 2H+ + 2e−

Denitrification is the process of reducing nitrate and nitrite, highly oxidised forms of nitrogen available for consumption by many groups of organisms, into gaseous nitrogen, which is far less accessible to life forms but makes up the bulk of our atmosphere. It can be thought of as the opposite of nitrogen fixation, which converts gaseous nitrogen into a more biologically available form. The process is performed by heterotrophic bacteria (such as Paracoccus denitrificans, Thiobacillus denitrificans, and various pseudomonads) from all main proteolytic groups. Denitrification and nitrification are parts of the nitrogen cycle.

Denitrification takes place under special conditions in both terrestrial and marine ecosystems. In general, it occurs when oxygen (which is a more favourable electron acceptor) is depleted, and bacteria turn to nitrate in order to respire organic matter. Because our atmosphere is rich with oxygen, denitrification only takes place in some soils and groundwater, wetlands, poorly ventilated corners of the ocean, and in seafloor sediments.

Denitrification proceeds through some combination of the following steps:

nitrate → nitrite → nitric oxide → nitrous oxide → dinitrogen gas
Or expressed as a redox reaction:

2NO3- + 10e- + 12H+ → N2 + 6H2O

Denitrification is the second step in the nitrification-denitrification process, the conventional way to remove nitrogen from sewage and municipal wastewater. It is also an instrumental process in riparian zones for the removal of excess nitrate from groundwater contaminated by fertiliser use.

Answer 2

google it, or open a text book. If you put effort into finding the information, then you'd know you did the work and remember most of the info you are looking for.Good Luck!