Photo: Gary Hayes
Basic science used to tell us that arsenic and lifeforms simply do not mix. Well, NASA’s new research has not only proved this statement wrong, but is expanding the definition of life as we know it!
In the harsh depths of California’s Mono Lake, researchers have discovered the first microorganism that uses the toxic chemical, arsenic, to survive and reproduce. It is a microbe called GFAJ-1, a member of a common group of bacteria, the Gammaproteobacteria.
Recipe For Life
To truly understand the shock that these scientists must have felt, we need to look at the basic chemistry of life. There are six basic building blocks for all known lifeforms on Earth. These are: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Arsenic did not make it on the list.
So how is this new microorganism able to exist?
Breaking The Rules Of Biochemistry
Scientists discovered that the microorganism is able to use arsenic as a substitute for phosphorus. Think of a baker using margarine instead of butter. They are two completely different things, performing the same function and getting virtually the same results.
In most lifeforms, phosphorus is an essential chemical component in the DNA and RNA of living cells. And for most lifeforms, substituting arsenic for phosphorus is a death sentence.
But not for GFAJ-1. When scientists replaced phosphorus with arsenic, not only was the microbe able to function, but arsenic became the new building block for reproducing cells.
If scientists are now proving the impossible, what else will they discover about life in the universe?
- IU Involved in New NASA Research on Arsenic Based Lifeform (Indiana Public Media)
- NASA Unveils Arsenic Lifeform (Wired Science)
- NASA-Funded Research Discovers Life Built with Toxic Chemical (NASA.gov)