Nitrogen Cycle Flashcards
The nutrient cycle
A nutrient cycle is defined as the cyclic pathway by which nutrients that circulate between living organisms, Hydrosphere, atmosphere and lithosphere like oxygen, nitrogen and carbon pass-through, in order to be recycled and reutilised. The pathway comprises cells, organisms, community and ecosystem.
What is the nutrient cycle essential for
The growth and development of living organisms
Water cycle
Continous cyclic movement of water between the earth and atmosphere
Define the nitrogen Cycle
cycle of nitrogen atoms through the living and non-living systems of Earth. The nitrogen cycle is vital for life on Earth. Through the cycle, atmospheric nitrogen is converted to a form which plants can incorporate into new proteins.
The nitrogen Cycle is essential for
For many biological processes. Living organisms need nitrogen to form amino acids which are the building blocks of protein.
Its unique chemical bonding properties allow it to create structures such as DNA and RNA nucleotides, and the amino acids from which proteins are built.Without nitrogen, these molecules would not be able to exist.
Backstory of nitrogen
Nitrogen was originally formed in the hearts of stars through the process of nuclear fusion. When ancient stars exploded, they flung nitrogen-containing gases across the Universe. When the Earth was formed, nitrogen gas was the main ingredient in its atmosphere. Today, the Earth’s atmosphere is about 78% nitrogen. This is an ideal balance because too much oxygen can actually be toxic to cells. In addition, oxygen is flammable. Nitrogen, on the other hand, is inert and harmless in its gaseous form
Nitrogen gas(NO2) occurs
In large amounts in the atmosphere However, nitrogen gas is not accessible to plants and animals for use in their cells
Pants can only use nitrogen
In the form of nitrates(NO3-)
Free nitrogen (N2) is converted unto nitrates in two ways
Electrical fixation by lightning and rain.
Nitrogen fixing bacteria by free living soil bacteria that snosrbs nitrogen from the spaces between the soil particles and convert it into nitrates
And by
Mutualistic nodule bacteria on the roots of the legumes that convert free nitrogen to nitrates for the plant. In exchange, the plant provides food and a secure habitat for the bacteria.
1-Nitrogen fixation
In the process of nitrogen fixation, bacteria turn nitrogen gas from the atmosphere into ammonia.
These nitrogen-fixing bacteria, often called “diazotrophs,” have an enzyme called “nitrogenase” which combines nitrogen atoms with hydrogen atoms. Ammonia is a nitrogen compound that can dissolve in water, and is easier for other organisms’ enzymes to interact with.Interestingly, the enzyme nitrogenase can only function when oxygen isn’t present.As a result, organisms that use it have had to develop oxygen-free compartments in which to perform their nitrogen fixation.
Nitrates in the soil absorbed by plants containing nitrogen
Is used to form plant proteins
Animals eat the plant and obtain
Nitrogen used to produce animal proteins.
When plants and animals die
Their bodies are broken down into ammonia by decomposition bacteria.
Another way ammonia is released is when
Excretion of animals containing the compound urea which is then converted into ammonia
Ammonia is broken down to nitrates by nitrifying bacteria in two ways
Ammonia to nitrites(no2-)
Nitrites (No2-) to nitrates (NO3-)