Consider the chemical reactions of the sulfur cycle shown in Figure 26.10. Oceans constitute the most significant reservoir of sulfur in the biosphere, and sulfate (SO₄²^-) reduction is the predominant form of anaerobic respiration in marine environments. In such cases, oxidized sulfur compounds like SO₄²^- are the electron acceptors instead of what?

Question

Quizplus · Accepted Answer

Anaerobic respiration occurs in the absence of oxygen, so oxygen cannot be the electron acceptor. Water is a product of aerobic respiration, not an electron acceptor. Hydrogen and carbon dioxide are involved in other types of reactions, but not in the sulfure cycle reactions or as electron acceptors in marine anaerobic respiration. The correct answer is B, as oxidized sulfur compounds are the electron acceptors in marine anaerobic respiration.

Consider the Chemical Reactions of the Sulfur Cycle Shown in Figure