Critical Review of: A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus
An experiment conducted by Evolutionary Geobiochemist, Dr. Felisa Wolfe-Simon on December 2nd, 2010, shows that the bacteria, christened GFAJ-1 appeared to incorporate arsenic into their DNA, lipids and proteins, is forcing a rethink of how life might look on other planets. The author’s purpose in writing this research paper is to establish the fact that a bacterium in a Californian lake appears to be able to use arsenic in its molecular make-up instead of phosphorus- even incorporating the toxic chemical into its DNA. This is significant because it goes against the general rule that all terrestrial life depends on six elements: oxygen, hydrogen, carbon, nitrogen, sulfur and phosphorus. These are needed to build DNA, proteins and fats and are some of the biological signatures of life that scientists look for on other planets. As far as NASA knows, this was this only experiment conducted and recorded on this specific subject.
By reading the title of the journal, one will know immediately what it is about. It’s straight to the facts. The overall introduction was clear and concise. It gives the readers a decent idea of what they are dipping their feet into without giving away the details which are explained later on in the passage. Something refreshing about the introduction is that it does not assume anybody is a science major. It explains the elements essential to life and goes on to explain why arsenic is not.
Methods of Experimentation and Research include a group of scientists gathered at Mono Lake located in eastern California. It’s a hyper-saline and alkaline water body with highly dissolved arsenic concentrations. They characterized the intracellular arsenic chemical environment, used cellular stoichiometry and elemental distribution, and traced the growth of the strain of bacterium. The procedures and methods of experimentation proved to be very solid. However, there...