I always knew I would need to memorize the amino acids and their properties, but I didn’t know when, or how serious it should be. Should I memorize everything about them? Should I do practice problems for them every day? Would it take a long time? Should I start in the summer? I was really stressed about it, and I was even more stressed when my professor said we needed to memorize them in a week. I went into full panic mode – everyone talked about how important memorizing them was. I couldn’t believe he gave me a weeks’ notice. I did what any good student would do: I started studying them for real two days before the exam. Why would I put myself through the stress of memorizing them if I didn’t have to? I did have to, by the way, I don’t know why I decided to study them last.
There are 20 major amino acids, the building blocks for proteins. They can be grouped by their properties: nonpolar, polar and uncharged, aromatic, polar and positive, and polar and negative. It was easiest for me to begin there. I started studying the groups individually. I began with connecting the name to the three-letter code, then the name to the one-letter code, then I made mnemonics using the one-letter code. After I felt comfortable with the groups and the overall properties, I began to study the structure.
Nonpolar: GAV LIMP
The nonpolar amino acids are glycine, alanine, valine, leucine, isoleucine, methionine, and proline. I think this is a common mnemonic, and poor Gav! He is limping so it has to stay out of any problems.
The structures for nonpolar amino acids are relatively simple. Glycine is the smallest amino acid, and the only achiral one, with its side chain being H. Next is alanine, which just has a methyl group. Proline has a ring that uses the amino group, and it helped me to remember that proline has a big circle (just as a p does). Valine looks like an upside-down V. Leucine is one more CH2; I remember leucine because it looks like the Eiffel Tower, which is in the City of Love. Isoleucine looks a little funny, it just has carbons and hydrogens connected all willy nilly, and it is a little long. I remember isoleucine because it looks awkward, and I don’t know how to say the name. Methionine contains a sulfur atom, but it is surrounded by methyl groups, which makes it nonpolar. There are only two amino acids that contain sulfur, and methionine is the nonpolar one.
Polar, uncharged: QTSNC.
My friend came up with this one, and it stuck to me like glue. Queen TS (Taylor Swift) New Cat. I remember this group is polar uncharged because Taylor Swift is well known (popular – polar), but her whole life isn’t known by the public. The polar uncharged amino acids are serine, threonine, cysteine, asparagine, and glutamine. I remember serine because it sounds like sirens, and sirens get right to the point (also, -OH sounds like the sound sirens make). Threonine is serine’s annoying younger sibling, and the -OH group is immediately on the first carbon. Cysteine is the other amino acid that contains sulfur; it is a small amino acid, so the sulfur makes it polar (not enough mass to counteract it). The next amino acid is asparagine (N), and this one was easy for me to remember because I (Nevaeh) love asparagus. I am also indecisive, so I get both O and NH2. The last amino acid in this category is glutamine (Q). I remember this one because my mom is a (Q)ueen, and it one ahead of (N)evaeh. Glutamine has one more -CH2 group than Asparagine (it is taller, so in my mind it is older and wiser).
Aromatic: FYW
There are only 3 aromatic amino acids, so this one was relatively easy. The first is phenylalanine, which is just a phenyl group after -CH2. It looks a little silly, and it has a (F)unny name. Next is tyrosine, and she looks like a tire with a boot on it. Tryptophan is the final amino acid, and this mnemonic is silly. The one-letter code is W, and I remember this because tryptophan only (W)ins. Tryptophan has two rings, which is why it always wins.
Negatively charged: DE
There are two negatively-charged amino acids, and they are both acids, which made this one easy for me – aspartic acid and glutamic acid – or as I know them, AsparDic acid and Glutamic Elizabeth acid. The structures are very similar; the only difference is that Glutamic acid is one more -CH2 longer than aspartic acid. I remember this because (E)lizabeth is longer than D.
Positively charged: KHR
I unfortunately don’t have a good mnemonic for remembering this group, except that the rest are memorized and you can use the process of elimination. The first amino acid is lysine (K), and I remember this because it has 4 -CH2 groups, and the letter K has 4 points (the line is one, then each corner/angel in the points). Next is histidine, which has a cyclic group with N. I remember this one because my name is NevaeH. So, histidine is a house made with N. The last amino acid is arginine, which is a little weird to remember. It has 3 nitrogens in groups, and it has 2 letter n’s in the name. When I was memorizing these, I didn’t realize it only had 2 n’s, and so I remembered this (with the incorrect spelling of arginine) by connecting the 3 nitrogen’s in the structure to the 3 n’s in its name (a little embarrassing, but not too much, because it worked).