1 / 27

Figure 4.4

The Nitrogen Cycle. Figure 4.4. While N 2 is the ultimate source and sink of biospheric nitrogen, several oxidized and reduced forms occur in the environment. . Nitrogen Fixation. Figure 15.17.

avari
Download Presentation

Figure 4.4

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 Figure 4.4

  2. While N2 is the ultimate source and sink of biospheric nitrogen, several oxidized and reduced forms occur in the environment. Nitrogen Fixation Figure 15.17

  3. Nitrogen-fixing bacteria may be free-living in soil or water, or they may form symbiotic associations with plants. - Rhizobium and legumes The Nitrogen Cycle Figure 4.5

  4. FeMoCo

  5. The nitrogenase complex includes two kinds of subunits: The Mechanism of Nitrogen Fixation - A protein with an iron-sulfur core (Fe protein) - A protein containing a complex of molybdenum, iron, and sulfur protein (FeMo protein) Electrons acquired by Fe protein (with energy from ATP) are transferred to FeMo protein to reduce nitrogen. Figure 15.19A

  6. Figure 15.20

  7. Figure 15.21B

  8. Nitrogen gas (N2) is fixed into ammonium ion (NH4+) only by some species of bacteria and archaea. Aquatic cyanobacteria develop special cells called heterocysts to fix N2. - Photosynthesis is turned off to maintain anaerobic conditions. Nitrogen Fixation Figure 15.18

  9. Figure 21.33

More Related