Sulfur cycle

Definition

The sulfur cycle is the process by which sulfur moves between rocks, waterways, and living systems. It involves various chemical transformations facilitated by microbial metabolism.

5 Must Know Facts For Your Next Test

1. Microorganisms play a crucial role in the sulfur cycle by oxidizing and reducing different sulfur compounds.
2. Sulfur-oxidizing bacteria convert hydrogen sulfide (H2S) into sulfate (SO4^2-).
3. Sulfate-reducing bacteria reduce sulfate to hydrogen sulfide under anaerobic conditions.
4. Dimethyl sulfide (DMS) is a significant volatile compound produced during the sulfur cycle, influencing cloud formation and climate.
5. The sulfur cycle is essential for synthesizing amino acids such as cysteine and methionine.

Review Questions

• What roles do microorganisms play in the sulfur cycle?
• How do sulfate-reducing bacteria contribute to the sulfur cycle?
• Why is dimethyl sulfide (DMS) important in the context of the sulfur cycle?

Related terms

Sulfate-Reducing Bacteria: Microorganisms that use sulfate as an electron acceptor, reducing it to hydrogen sulfide.

Sulfur-Oxidizing Bacteria: Bacteria that oxidize reduced sulfur compounds like hydrogen sulfide into sulfate.

Biogeochemical Cycles:

The natural pathways by which essential elements circulate through ecosystems involving biological, geological, and chemical processes.