1 / 7

The nitrogen cycle

The nitrogen cycle. Why is the cycle important and what is nitrogen used for?. Not many organisms can use nitrogen directly from the air (78%) Recycling of nitrates allows plants to manufacture proteins for growth. Therefore it is a limiting factor for yield/ dry mass. 4 Main stages.

saeran
Download Presentation

The nitrogen cycle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The nitrogen cycle

  2. Why is the cycle important and what is nitrogen used for? • Not many organisms can use nitrogen directly from the air (78%) • Recycling of nitrates allows plants to manufacture proteins for growth. • Therefore it is a limiting factor for yield/ dry mass

  3. 4 Main stages • Ammonification- production of ammonia from organic compounds. • Nitrification- Conversion of ammonium ions to nitrate ions. • Nitrogen fixing: • 1) Free living bacteria- nitrogen gas reduced to ammonia. • 2) Mutualistic bacteria- symbiotic relationship with plants. • Denitrification- Conversion of ammonium ions to gaseous nitrogen.

  4. Non-living/ living stages • Nitrogen in the soil is classed as a non-living phase of the cycle. • When ions are absorbed or fixed through nodules into producers, consumers and decomposers the ammonium in the macromolecules becomes part of the living phase.

  5. Final links/ processes in the cycle • Death and excretion- Saprobiotic organisms break down urea or dead organisms into ammonium ions. • Absorption- Nitrate ions actively transported through root hair cells. • Feeding- Consumers obtain nitrates from digestion.

  6. Put it all together Non-living living Nitrogen fixing (free living bacteria) Ammonium ions Nitrogen in the atmosphere Nitrite ions Nitrate ions Nitrification De-nitrification Nitrogen fixation (mutualistic bacteria) Absorption Ammonium containing molecules (protein) Producers Ammonium containing molecules (protein) Consumers Digestion Death Death and excretion Ammonification Ammonium containing molecules (protein) Decomposers

  7. Typical questions • Where and how does nitrogen entre the living and non-living stages of the nitrogen cycle? • How is nitrogen recycled in the nitrogen cycle? • Why do farmers achieve a faster rate of crop growth when they plough?

More Related