Arsenic – Venomous or Vital for Life?

Arsenic. Just the thought of the compound sickens many due it its infamous toxic properties.  Who would’ve thought that a compound this hazardous to most organisms could be one of the building blocks of life for another?

A recent discovery of microorganisms in Mono Lake, California shocked geneticists and scientists all over the world. This past December, NASA proclaimed that they had discovered the first known organism on Earth that utilizes arsenic as one of its chemical means of life and survival. Though some bacteria are known to obtain their energy by oxidizing arsenic as a fuel, Prior to this discovery, every known organism on Earth had used carbon, nitrogen, phosphorous, oxygen, sulphur, and hydrogen as the six fundamental elements of life. This organism discovered has been found to replace the phosphorous in the classic combination, with arsenic – using it as a staple backbone in its hereditary units and as an energy-carrying molecule.

Some researchers believe that due to the harsh conditions within Mono Lake, (high levels of saline, alkanes, and arsenic – fun fact, the lake actually has a layer of dead flies floating around the circumference of its surface) the organism may have evolved to adapt to the depleting levels of nutrients and utilize other chemicals present – a process that could have taken who knows how long.

It’s mind-boggling to believe that the discovery of one miniscule, seemingly insignificant organism has completely changed the way scientists viewed the way life has survived. This ‘seventh’ core element can only lead those to wonder what other microorganisms are waiting to be discovered that could potentially utilize fluorine as a main structural component, or harness radio waves as energy.

What about life beyond the planet Earth? Could this discovery just prove that complex species may be thriving in the inhuman conditions of the other planets?

2 responses to “Arsenic – Venomous or Vital for Life?

  1. Also, just found a page on “Hypothetical types of biochemistry” if anyone is interested:
    http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry

  2. I think that this discovery is incredibly important for our notions concerning life. If arsenic can be incorporated as a building block, then what else can? It makes us reexamine how we look for life on other planets.

    We used to say that life was scarce in the universe because Earth had the “perfect conditions” to support it but it would seem now that if alternate forms of life can exist, we’re not limited to looking at “Goldilocks” regions in space.

    Great post!