Video Transcript
Which of the following molecules is
classified as organic? (A) Water, (B) sodium chloride, (C)
carbon dioxide, (D) oxygen, or (E) glucose.
In order to answer this question,
we first need to recall the definition of an organic molecule. All living organisms require
different types of nutrients to sustain life. Those nutrients can be classified
into organic or inorganic molecules. Organic molecules are compounds
that contain carbon and hydrogen atoms joined together. On the other hand, inorganic
molecules are those that do not contain carbon–hydrogen bonds.
Let us compare the structure of
each molecule in our answer choices to arrive at the correct answer.
The molecular formula for water is
H2O. This means that two hydrogen atoms
and one oxygen atom are contained in one molecule of water. The oxygen atom, in this case,
becomes the central atom bound to each hydrogen. Because water does not contain a
carbon atom bound to hydrogen, it is not considered organic and can be omitted from
our answer choices. Sodium chloride, which is commonly
known as table salt, has the molecular formula NaCl. You may have noticed that NaCl does
not contain any carbon or hydrogen molecules. Therefore, it is not organic.
Answer choice (C), carbon dioxide,
refers to a compound with the molecular formula CO2. While carbon dioxide does contain a
carbon atom, it does not contain any hydrogen atoms. Therefore, carbon dioxide is not an
organic compound. Molecular oxygen, or O2, is
composed of two oxygen atoms joined by a double bond. This is the oxygen that we breathe
in each and every day. Oxygen does not contain carbon or
hydrogen atoms, so it is not considered organic.
Finally, the molecular formula of
glucose is C6H12O6. Because glucose contains carbon and
hydrogen bonded together, glucose is considered an organic molecule. Therefore, the answer to this
question is (E), glucose.
