The Nitrogen Cycle Major Processe s n Nitrification

The Nitrogen Cycle Major Processe s: n Nitrification n Denitrification n Decompositio n Denitrification Nitrogen Fixation Nitrification

Components of the Nitrogen Cycle n N 2 n (nitrogen gas) In the atmosphere; cannot be used by plants or animals n NH 3 n (ammonia) Found in soil; cannot be used by plants or animals n NO 2 (nitrite) n Found in soil; cannot be used by plants or

Components of the Nitrogen Cycle (Continued) n NO 3 n (nitrate) & NH 4+ (ammonium) Only compounds of nitrogen that plants can use n Various nitrogen compounds such as amino acids n Many different compounds that living things need for survival

Processes of the Nitrogen Cycle Nitrification: n The process by which unusable nitrogen compounds are changed into compounds used by plants and animals. n Ex: Conversion of nitrogen gas (N 2) to ammonium (NH 4+) n n Carried out by nitrogen-fixing bacteria Ex: Conversion of nitrogen gas (N 2) to nitrate (NO 3 -) n Occurs when lightening strikes

Processes of the Nitrogen Cycle Denitrification: n The process of changing complex nitrogen compounds into atmospheric nitrogen n Ex: Conversion of nitrate (NO 3 -) to nitrogen gas (N 2) n Carried out by denitrifying bacteria

Processes of the Nitrogen Cycle Decomposition: n The process of changing dead plants & animals into simple nitrogen compounds. Assimilation: n The process of changing usable nitrogen compounds by plants into complex plant or animal nitrogen compounds.

Switch to handout on Nitrogen Cycle

Question of the day: n What are the four stages in the nitrogen cycle? And in what order? n The nitrogen cycle would not function without these two key organisms: n Name a legume plant and define what that means.

Back of Nitrogen Cycle Handout… 1. What source of energy ultimately drives the nitrogen cycle? Explain. The Sun: It gives plants the energy to absorb soil nitrates (NO 3) - so the plant can make protein and grow.

Back of Nitrogen Cycle Handout… 2. How do animals obtain nitrogen as shown in Figure 3 -13? Animals eat plant or animal protein to get “N”. They digest it and then use amino acids to make protein.

Back of Nitrogen Cycle Handout… 3. In what form does nitrogen appear in the air? Where does it come from? N 2 (nitrogen gas). Bacteria break down plant & animal protein and N compounds in soil.

Back of Carbon Cycle Handout… 4. What form on nitrogen are most plants able to absorb? How does it get into that form? Nitrates (NO 3) Special bacteria (nitrogen-fixers) are in little nodules on roots of certain plants-legumes. Ex: Clover, peanuts, soybeans, alfalfa You can cross out #5 on your sheet

Review Video n https: //www. youtube. com/watch? v=Lb. Bg. P ekjiyc

Mineral/Rock cycle Living organisms need other minerals, like Ca, Mg, Fe, etc. n They come from the releasing of minerals from rocks. n n So, how does the rock cycle work and how are minerals incorporated in the environment?

The mineral cycle * See page 33 of textbook

What to study: n n n HW from textbook and any textbook readings Class notes Food web diagrams, concept map, N, C and H 20 cycle diagrams Vocabulary Case Study: Reintroduction of Wolves