Elements in living cells

Bray D Protein molecules as computational elements in living cells. Nature 1995 376 307. 

Carbon is the most prevalent element in living cells. Carbon defines organic chemistry. Some predict that carbon-11 will someday become the most important radionuclide in nuclear medicine, although lluorine-18 and technetium-99m hold that position today. 

FIG. 2.1. The Periodic Table of the elements, the full understanding of which provides ideally a reductionist approach to the explanation of chemistry. The essential bulk and trace elements for living cells are also shown but knowledge of them is not in any way adequate for an explanation of biology... 

Although the RNA world remains a hypothesis, with many gaps yet to be explained, experimental evidence supports a growing list of its key elements. Further experimentation should increase our understanding. Important clues to the puzzle will be found in the workings of fundamental chemistry, in living cells, and perhaps on other planets. 

Two of the four most abundant elements in living systems, hydrogen (H) and oxygen (O), combine to form water, H20. Without water there would be no life as we know it. The human body is largely made up of water. Water dissolves other life-supporting substances and transports them into and around cells. It is also a liquid in which important biochemical reactions take place. 

Aluminium is an environmentally abundant element and has no known biological function in living cells. On the other hand, A1 exhibits biological toxicity as demonstrated in experimental models." " Intake and output of aluminium for the healthy population from various sources, biological monitoring of occupational aluminium exposure in serum and speciation analysis of the amount and composition of A1 species with high and low molecular masses, have been reviewed by several groups. Besides the use of mass spectrometric and non-mass spectrometric techniques (e.g., ETAAS after separation of human serum proteins ) ESI-MS-MS analysis has also been performed to identify the A1 species. 

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