This post is more or less a "part 2" based on my last post.
After writing my last blog, I found myself still questioning some things related to arsenic, and I figured you might be too!
So the first thing that comes to mind, is what IS the difference between organic and inorganic arsenic?
Now according to medicinenet.com July 2, 2010 "Organic arsenic exposure can occur by eating food. Organic arsenic is 500 times less harmful than inorganic arsenic".
Ok, so lets talk chemistry. I mean... isn't "arsenic", well... arsenic?!
You may have learned from chemistry classes... way back when, that an organic compound is any compound (of elements) which contain carbon. There are a few different ways that the arsenic element (As) can combine with carbon and oxygen, nitrogen, chlorine, etc. to form a type of "organoarsenic" compound. In all of the organic compounds, however, one element MUST be connected to arsenic (As)... that is carbon.
So an inorganic compound then is any compound which does not have carbon. We see that often arsenic combines with oxygen to create a colorless, odorless, water soluble, crystalline. Such is the case with As2O3 for example ("white arsenic"). Or various sulfur compounds can be created As2S3 and As4S4.
Anyways... now on to my most favorite fun fact about arsenic...
Last year, you may recall reading about a discovery that NASA had made: A new bacteria was discovered which creates DNA with arsenic!!!
Awesome right?!
Taken from National Geographic.com December 2, 2010:
"A new species of bacteria found in California's Mono Lake is the first known life-form that uses arsenic to make its DNA and proteins, scientists announced today.
Dubbed the GFAJ-1 strain, the bacteria can substitute arsenic for phosphorus, one of the six main "building blocks" for most known life. The other key ingredients for life are carbon, hydrogen, oxygen, nitrogen, and sulfur.
Arsenic is toxic to most known organisms, in part because it can mimic the chemical properties of phosphorus, allowing the poison to disrupt cellular activity.
The newfound bacteria, described online this week in the journal Science, not only tolerates high concentrations of arsenic, it actually incorporates the chemical into its cells, the study authors found.
"It's gone into all the vital bits and pieces," said study co-author Paul Davies, director of the BEYOND Center for Fundamental Concepts in Science at Arizona State University in Tempe.
While for now Earth is the only place we know that life exists, the discovery does hold implications for the search for life elsewhere in the universe, since it shows that organisms can exist in chemical environments biologists once wouldn't have imagined."