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Evolution of metal ions in biology

Natural development of chemicals and elements challenged organisms to adapt or die. Current organisms require redox reactions to induce metabolism and other life processes. Metals have a tendency to lose electrons and are important for redox reactions.

“Metals have become so central to cellular function that the collection of metal-binding proteins (referred to as the metallomes) accounts for over 30% of all proteins in the cell. Metals are known to be involved in over 40% of enzymatic reactions, and metal-binding proteins carry out at least one step in almost all biological pathways” (Monosson - Evolution in a Toxic World).

Unfortunately, metals are also toxic so a balance must be acquired to regulate where the metals are in an organism as well as how much is in an organism. Many organisms have flexible systems in which they can exchange one metal for another if one is scarce. Metals in this discussion are naturally occurring elements that have a tendency to undergo oxidation. The essential metals are vanadium, molybdenum, cobalt, copper, chromium, iron, manganese, nickel, and zinc. These are deemed essential because without them biological function is impaired.

The Earth started off as an iron aquatic world with low oxygen. As the great oxidation event occurred, iron became insoluble (as did other metals) and scarce while other metals became soluble. Sulfur was a very important element during this time. Once oxygen was released into the environment, sulfates made metals more soluble and released those metals into the environment; especially into the water. Moving from the oceans to land causes another change of available metals; which made metals even more tightly regulated.

One hypothesis proposed for how elements became essential is their relative quantity in the environment as life formed. This has produced research on the origin of life; for instance, Orgel and Crick hypothesized that life was extraterrestrial because the alleged low abundance of Molybdenum on early Earth (it is now suspected that there were larger quantities than previously thought). Another example, is life forming around thermal vents based on the availability of zinc and sulfur.

Contributions to Evolution of metal ions in biological systems:

What are metallic ions? Distinction between major and minor metal ions. Are these the only metals? Is it only weathering that has caused integration of metals into metabolic pathways? Spelling and grammar edits needed. Introduction to catalysis section needs to be added.

*Added section on evolution/history of related inorganic elements during the development of the Earth. Why was it important to integrate these elements into biological life?

Williams, R., & Rickaby, R. E. M. (2012). Evolution's destiny : Co-evolving chemistry of the environment and life. Cambridge, UK: RSC Pub.

Dupont, Christopher L., Andrew Butcher, Ruben E. Valas, Philip E. Bourne, and Gustavo Caetano-Anollés. “History of Biological Metal Utilization Inferred through Phylogenomic Analysis of Protein Structures.” Proceedings of the National Academy of Sciences of the United States of America 107, no. 23 (June 8, 2010): 10567–72. doi:10.1073/pnas.0912491107.

Monosson, Emily. Evolution in a Toxic World. Washington, DC: Island Press/Center for Resource Economics, 2012. doi:10.5822/978-1-61091-221-1.

Williams, R., & Fraústo, D. S. J. (2005). The Chemistry of Evolution : The Development of our Ecosystem. Burlington, NL: Elsevier Science. Retrieved from http://www.ebrary.com

WIKI ED BIOCHEMISTRY EDIT SUGGESTIONS:

"In agriculture, biochemists investigate soil and fertilizers, and try to discover ways to improve crop cultivation, crop storage and pest control." - Needs citation

"Depending on the exact definition of the terms used, molecular biology can be thought of as a branch of biochemistry, or biochemistry as a tool with which to investigate and study molecular biology." - seems like an opinion

"The mechanisms by which cells harness energy from their environment via chemical reactions are known as metabolism." - citation needed

"The mechanisms by which cells harness energy from their environment via chemical reactions are known as metabolism." - unusual placement, needs to be in a different paragraph.

History section has timeline ordering that is off specifically the section about Lavoisier

All text following - Starting materials: the chemical elements of life - need citations.

WIKI ED Bioenergetics EDIT SUGGESTIONS:

Whole article needs citations

Introductory paragraph/sentence needs more information added and needs rewording.

Needs more organizing

More information on thermodynamics, types of energy pathways, Gibbs free energy