What Poison? Bacterium Uses Arsenic to Build Dna and Other Molecules

What Poison? Bacterium Uses Arsenic to Build DNA and Other Molecules

In the article What Poison? Bacterium Uses Arsenic to Build DNA and Other Molecules, Elizabeth Pennisi states that the poisonous arsenic can sustain life by referring to the experiment completed by Felisa Wolfe-Simon. All living organisms depend on phosphorus, hydrogen, oxygen, carbon, nitrogen, and sulfur. Wolfe-Simon and two colleagues believed arsenic, which is a grayish white element with a metallic luster, could have replaced phosphorus many years ago. Wolfe-Simon noticed that arsenic was directly below phosphorus on the periodic table and they both share similar chemical properties. To test their hypothesis they collected mud from the Mono Lake in California which is known for having high arsenic levels and grew organisms in it in an increased area of arsenic. One day they checked the dish and saw surviving bacteria. All of the scientists were shocked as they never believed a living organism could survive with no phosphorus. Many tests showed that some of the bacteria did in fact grow with the use of arsenic. They named this new bacteria GFAJ-1. This experiment became very controversial; some scientists said that the arsenic was just part of the bacteria’s cells and not part of their biochemistry. They concluded that organisms like GFAJ-1 could have thrived in arsenic laden vents, which many say is how life on earth formed.

I enjoyed reading the article and thought it was interesting that people are trying to find out and experiment on elements. I found it intriguing that they didn’t believe that they would be able to stimulate life in the arsenic dish, they just wanted to try. I also thought that they could have improved there experiment by having a control, maybe growing organisms in a phosphorus dish to see how they are different. Also they could have multiple dishes of arsenic in case one dish had organisms that were already damaged. Since some scientists disagree with their...