Extra Knowledge:
How to Draw Aspirin
Throughout Aspirin Adventures we've been
showing you this picture of the aspirin molecule, the one you see on the
right. If these pictures leave you a little confused, we hope this page will
clear things up and make some sense of these pictures.
The amazing
aspirin
molecule.
Aspirin is acetylsalicylic acid, which is a big name that doesn't mean a whole lot. Okay, it means a little bit, but we'll talk about that later. Everything around us is made of tiny molecules, most too small to see. Molecules are made of atoms. The strange drawing on the right is just a blueprint of what kind of atoms are in the aspirin molecule, and how they are arranged. This and other strange symbols and drawings used in chemistry are pictures of molecules, the molecules which make up everything.
Most molecules are made of more than one kind of atom. An aspirin molecule is made up of carbon atoms, hydrogen atoms, and oxygen atoms. Now, as a special treat, we're going to show you what an aspirin molecule looks like in 3-D:
| Color code:
 gray = carbon
(C)
Click and drag the molecule |
|
white = hydrogen
(H)
red = oxygen (O)
But even though a real aspirin molecule is three-dimensional, a piece of paper is flat, so we have to draw the molecule flat. We can draw it flat like this:
 |
O = oxygen atom H = hydrogen atom |
Don't be intimidated by this complicated picture. It's not as bewildering as it looks. Let's explain. The letters C, O, and H, of course, are atoms of carbon, hydrogen, and oxygen, respectively. A line drawn between two atoms shows that those two atoms are sharing a pair of electrons. That is to say, two electrons are orbiting both of the atoms joined by the line. Two lines mean four electrons are being shared instead of just two. This sharing joins one atom to another. The joining of two atoms by sharing electrons is called a covalent bond.
That picture up there is what we call the molecular structure of the aspirin molecule. That structure is complicated to look at, and it takes a lot of time to draw. So, we make it simpler when we want to draw it. For example, we usually draw that carbon atom with three hydrogens joined to it as "CH3." It is shown in red in the picture below.
Okay, now it's a little simpler. But we can simplify this drawing even more. Look at that ring of six carbon atoms, joined by single and double bonds (lines) alternating. This is so common that we normally draw it as just a hexagon with alternating double and single bonds. We don't draw the carbon atoms in the ring, or the hydrogens attached to them, either.
Now you know that this mess of letters and lines is really a shorthand way of drawing a bunch of atoms arranged in a specific manner to form a molecule, that is, a shorthand way of drawing a molecular structure. We have one more thing to talk about now: the name acetylsalicylic acid. Why do we call aspirin by this big name? As you remember, before there was aspirin, people used salicylic acid as a pain reliever. The name salicylic acid means "acid from the willow tree" because salix is the scientific name for the willow.
Since Felix Hoffmann added a group of atoms to the salicylic acid molecule that we call an acetyl group, the new molecule is called acetylsalicylic acid.
In addition to learning what our picture of an aspirin molecule means, you've now learned a little bit about how atoms are put together to form molecules. You might be ready now to Build Your Own Molecule.
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