ORGANIC MOLECULES There are so many molecules possible in nature—from individual atomic molecules (which are as numerous as the number of elements in the periodic table) to very large macromolecules made from at least a thousand different atoms that have somehow found themselves together in not only the same vicinity but connected to one another in a very specific way. There are thousands of possible combinations of atoms in nature; the vast majority of the molecules in nature have only four different atoms in them: these are carbon, hydrogen, oxygen, and nitrogen. In fact, it can easily be said that, of these, it is carbon that defines life as being life and that defines a given molecule as being “organic” or belonging to life. Of course, there are other atoms in life, such as sulfur, phosphorus, and minerals like magnesium, iron, and zinc. These arguably are necessary for life but, at least here on earth, they do not define life. (As you’ll see, water is necessary for life as well but in a different way). Organic molecules are completely built upon chains of carbon atoms. These chains, at least in life forms as we know them, are extremely long. You may ask, why carbon and what’s so special about it? Without getting deep into biochemistry, suffice it to say that carbon has the unique ability to bind to four other atoms at the same time. This leads to chains of carbon atoms that can combine to connect to other carbon atoms as well as to other molecules. Carbon has the unique property of also being able to form rings rather than lining up in single file. This ability to combine with other atoms as well as to form rings makes for an incredible variety of different molecules that can be made from it. You should know that organic molecules aren’t confined to living things. There are many carbon-based things in nature, such as fossil fuels, which are actually the remains of living organisms that once survived on earth. Manmade molecules, such as pesticides, medicines, and plastic substances are considered organic because of their molecular structure. There are organic components to much of what we see in life around us, such as cologne, shampoo, rayon fabric, nylon fabric, cotton, detergent, and cleaning products.
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