Nitrogen Cycle
What is Nitrogen? Nitrogen makes up about 78% of our atmosphere. Nitrogen in the atmosphere it is mostly in the form of ______, which is a compound that plants and animals cannot use. The process of converting nitrogen into compounds that can be used by plants and animals is called the ______________________. N2 Nitrogen Cycle
Why we care about nitrogen… Nitrogen is an essential component of _____________________.The building blocks of life. DNA, RNA and Proteins
How does atmospheric nitrogen (N2) get changed into a form that can be used by most living organisms? Four By traveling through one of the ________ processes in the Nitrogen Cycle! (1) Nitrogen Fixation (4) Denitrification Nitrogen Cycle (3) Nitrification (2) Ammonification
Process 1: Nitrogen Fixation ___________________ is the process in which the N2 compound in the atmosphere breaks and combines with other compounds. The nitrogen is _________ when it combines with ______________ or _______________. “fixed” hydrogen oxygen N N H N2 N H H Nitrous Oxide (N2O) Ammonia (NH3)
Three ways to “fix” Nitrogen bacteria Main process: Special ____________ convert the nitrogen gas (N2) to ammonia (NH3), which only ________ plants can use (peas, beans). _________________ strikes convert N2 to N2O or NO3. Industrial production. ____________ manipulation turns N2 into NH3 (Fertilizer) some Lightning Chemical
Process 2: Ammonification _____________________ - After all the living organisms have used the ___________________, decomposer bacteria convert the nitrogen to _______________. Ammonification organic nitrogen ammonia H N H H Ammonia Bacteria Organic Nitrogen (proteins)
Process 3: Nitrification H _______________ is the process that converts ammonia (NH3) into nitrites (NO2) and nitrates (NO3) which ____ plants _______ use. Note: Ammonia comes from ______ nitrogen fixation and ammonification How is it done? _____________________ Nitrification N H H most can Both O O N O N Bacteria! O O
Process 4: Denitrification _______________: Process in which nitrogen compounds _____________________ into atmospheric nitrogen (N2 or N2O). The main process is performed by _____________________ in the soil. It can also happen by _____________ fossil fuels. Denitrification convert back bacteria burning N2 NO3 N2O
N2 N2O NO3 NH3 (1) Nitrogen Fixation (4) Denitrification Nitrogen Cycle (2) Ammonification NO3 NH3 (3) Nitrification Ammonia is converted to nitrites and nitrates. Nitrates in Soil Organic nitrogen is converted to ammonia.
decomposition by bacteria & fungi Nitrogen in the air nitrogen fixing plant eg pea, clover animal protein plant made protein dead plants & animals urine & feces denitrifying bacteria root nodules (containing nitrogen fixing bacteria) decomposition by bacteria & fungi nitrates absorbed nitrates ammonia bacteria nitrites bacteria (nitrifying bacteria)
Human Impact Combustion Commercial Fertilizers mineral deposits ___________________, releases toxic nitrogen compounds into the atmosphere. ____________________________ release nitrous oxide into the atmosphere and introduce excess nitrogen into the environment. Remove nitrogen from the soil when we mine it for nitrogen rich __________________________. Discharge of ___________________________ releases excess nitrogen into the water ecosystems which disrupts the aquatic balance and kills fish. Commercial Fertilizers mineral deposits municipal sewage
Commercial Fertilizers #1 Are the ______ contributor of new nitrogen in the nitrogen cycle. Added because nitrogen is a ________________ for plant growth. Problems: hard to apply fertilizer and keep it in one area. Runoff, evaporation, etc.. So farmers apply about ___________________ as they need. Extra nitrogen disrupts the ________________. limiting factor twice as much food chain
Exit Ticket What are the four main processes of the nitrogen cycle? What is it called when bacteria convert nitrogen into ammonia? What organism is required for every step of the nitrogen cycle?