ch. 4: steps of nitrogen cycle

Denitrification

Denitrifying bacteria in oxygen-poor soil and stagnant water convert nitrate (NO3-) into nitrous oxide (N2O) and eventually back into nitrogen gas (N2)

NO3

most usable, nitrate

step 3: assimilation

plant roots absorb new form of nitrogen.

Ammonification

Decomposers in soil and water break down nitrogen compounds into ammonium (NH4+)

Plants take up both ammonium and Nitrate by which process?

Assimilation

What is the chemical equation for ammonium

NH4+

What is the chemical equation for Nitrate

NO3-

Nitrification

Nitrifying bacteria convert ammonium (NH4+) into nitrite (NO2-) and then into nitrate (NO3-)

What are the two processes by which nitrogen is made available to organisms?

Nitrogen Fixation and Nitrification.

What is the process of Nitrogen Fixation?

Nitrogen combines with Hydrogen to form ammonium.

Nitrogen Fixation

Nitrogen fixation converts N2 from the atmosphere. Biotic processes convert N2 to ammonia (NH3) whereas abiotic processes convert N2 to nitrate (NO3-)

Assimilation

Producers take up either ammonium (NH4+) or nitrate (NH3-). Consumers assimilate nitrogen by eating producers

Nitrogen helps build what?

Proteins and DNA

Both Nitrogen Fixation and Nitrification are carried out by what?

Specialized Bacteria

What is the process of Denitrification?

Specialized denitrifying bacteria remove oxygen from Nitrate and release nitrogen back into the atmosphere.

What is the process of Nitrification?

What is the process of Nitrification? Nitrifying Bacteria convert ammonium to nitrate.

N2

atmospheric nitrogen, 78% of our air but unusable

step 5: denitrification

bacteria turns the decomposed matter back into N₂O, which is released into atmosphere; repeat cycle.

step 1: nitrogen fixation

conversion of atmospheric NO₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 4: ammonification

conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

nitrifying bacteria

makes nitrogen usable NH4 -> NO2 --> NO3

step 2: nitrification

process of converting ammonia to nitrite or nitrate. nitrITE -->nitrATE