Question

What is the definiton of inorganic molecules?

Technically speaking, a molecule is the smallest fundamental unit of a compound that can take part in a chemical reaction. Organic molecules are those that always involve the bonding of carbon and hydrogen somewhere in their molecular structure. Inorganic molecules generally involve non-carbon chemistry; however, there are exceptions (carbon dioxide, for example). This distinction between organic and inorganic is important because organic chemistry is the chemistry of life. All life on Earth is composed of primarily organic molecules. Organisms do however rely on inorganic molecules such as water (H20) and salt (NaCl) for function and support. Carbon is singular in the ability to form large, diverse, and complex molecules. It is one of the core prerequisites for life as we know it. Some scientists have investigated the idea that other elements, such as silicon, could be able to perform chemically similar to carbon in hypothetical organic systems: to find out more, check out Ask-an-Astrobiologist’s featured question on this fascinating, fundamental topic: http://nai.arc.nasa.gov/astrobio/feat_questions/silicon_life.cfm. You might also find the following question in our archive useful: http://nai/astrobio/astrobio_detail.cfm?ID=229 David Lamb, Science Projects Specialist, NAI
October 24, 2002