2. Sulfur Cycle Rachel Franks, Rakin Hamad, and Elliot Beard

3. Sulfur Sulfur is a brittle, yellow, tasteless and odorless nonmetallic element Big part of vitamins, proteins and hormones Plays a big part in climate and the health of many ecosystems

5. Chemical Reactions Mineralization of organic to inorganic sulfur An example the degradation of cysteine - R - HS - CH 2 - CHNH 2 - CO 2 H ( cysteine ) ------ -> NH 3 + R - HS - CH 2 - CO - CO 2 H ( Beta - mercaptopyruvic acid )------> H 2 S + CH 3 - CO - C 2 H ( pyruvic acid ) ------> utilized in a number of ways for metabolism

6. Chemical Reactions Oxidation of sulfide and elemental sulfur The main sulfur oxides are achieved by burning sulfur -S + O 2 → SO 2 SO 2 + 1/2 O 2 → SO 3

7. Chemical Reactions Reduction of sulfate to sulfide Usually sulfate is converted to sulfide using this formula -SO 4 2- + PAP (phosphoadenosine-5-phosphate)--- ---> PAPS (phosphoadenosine-5- phosphosulfate------->PAPS + reduction------ >PAPS-reductase------> Sulfite---- >Thiosulphate---->Sulfide

8. Chemical Reactions Microbial immobilization of sulfur compounds and merging into organic sulfur Usually sulfur is converted to protein using : - SO 4 2 + PAP ( phosphoadenosine -5- phosphate )- -----> PAPS ( phosphoadenosine -5- phosphosulfate -------> PAPS + reduction ------> PAPS - reductase ------> Sulfite ----> Thiosulphate ----> Sulfide - ---> a series of biochemical steps ---- > methionine ----> sulfur containing protein.

9. Inorganic Sodium dithionite, Na 2 S 2 O 4 Thiosulfates (S 2 O 3 2− ) Sulfites (SO 3 2− ) Sulfides (S 2− ) Sulfates (SO 4 2− )

10. Organic Thiols Thioethers Sulfoxides Sulfonium Thiolates Sulfones

11. Pathway of Movement

12. Physical process like wind and erosion by water Geological events like volcano eruptions Biological activity Chemical reactions

13. Human Intervention Burning of fossil fuels and processing of metals has increased the amount of Sulfur in the air and ocean It also has used up the sedimentary rock sink

14. Human Intervention Create huge changes in the yearly flux of sulfur in the atmosphere The increased Sulfur in the atmosphere has reacted with other pollutants and causes acid rain

15. Work Cited "Sulfur Cycle." The Environmental Literacy Council. Web. 22 Nov. 2010.. Corbin, Katie. "Biochemical Cycles." Environmental Microbiology. Virginia Polytechnic Institute and State University. Web. 19 Nov. 2010..

16. Work Cited "Sulfur Cycle." Water Treatment and Purification - Lenntech. Web. 22 Nov. 2010.. "Environmental Decision Making, Science, and Technology." Mac OS X Server. Web. 22 Nov. 2010..

17. Questions What color is sulfur? Name an organic and inorganic sulfur compound? How Human’s intervention in the sulfur cycle effected the climate?

18. THE END