Here is the way I group them in my head for memorizing, please notice that I do not necessarily group like polarity, charge, etc., I figure that can easily be done by examining the structures once you know them:
For gluatmic acid and glutamine and aspartic acid and asparagine I remember that the "ines" are the amide derivatives of the acids. With asp____ I remember that there is only one carbon before the carbonyl carbon (C=O) and with glut____ I remember that there are two carbons before the carbonyl carbon.
I like to group serine and cysteine together. Serine is one carbon then an alcohol, whereas cysteine is one carbon then a thiol.
Glycine is the achiral amino acid with a simple hydrogen for its R group, Alanine has a simple carbon for its R group. Phenylalanine has a benzene ring attached to the simple carbon found in alanine (This makes sense, if you remember for organic chemistry "phenyl" means the benzene ring is directly attached to something, ie. phenyl alcohol, aka phenol.) Tyrosine takes that benzene ring in phenylalanine and makes it a phenol, where the alcohol is attached para to the amino acid chain.
Since I just mentioned Tyrosine I think it's a good time to bring up Threonine. I think of the T-words as the complicated alcohols. Tyrosine has the ring, because it is shaped like a tire. Threonine is like serine (The simple alcohol) with an extra carbon attached to the first carbon in the R group. Hey while we're going with letters, the complex T's follow the simple S alphabetically.
Valine's R group is in a V formation (three carbons attached to the amino acid in the middle of them, flaring out the end carbons in what looks like to me as a V). The leucines (leucine and isoleucine) both have four carbons. Leucine is like valine but the attachment is on the first carbon of alanine rather than directly to the main Amino acid backbone. Isoleucine resembles valine directly but one of the sides of the V has another carbon attached to it. As you may have guessed this makes the R group chiral but I wouldn't worry about it.
Proline is crazy, the 3 carbon long R group is attached directly to the amino portion of the amino acid backbone. Thus, there are cis and trans forms of proline but I wouldn't worry about it.
Tryptophan is nuts and hey it makes sense because the word looks weird and it's single letter abbreviation is W which stands for weird (haha not really). Its structure is the basic structure of a purine, but you probably don't know the structure of purines yet (remember what those are? The A's and G's in Genetics!)
Methionine is good stuff, as many of you remember it is the amino acid that is on the Amino-acyl TRNA with the start anticodon. the THIO in methionine tells you that it has a sulfer in it. It has three carbons in it, with the sulfur acting as a thioether between the first two carbons and the third. C-C-S-C
Lysine's R group is an Amine. Four carbons and then the amino group sticks right on it. I typically abbreviate it R= -(CH2)4-NH3+.
Histidine is a really important amino acid located in the active sites of enzymes. This is because its pKa is closest to the physiological pH. It's a funky ring attached to the R group of alanine.
Finally we have arginine. This guy is just plain creepy looking. There are three nitrogens in the R group. There is a lot of resonance going on here. After three carbons, a nitrogen attaches and this nitrogen is part of a triad of nitrogens that surround a centrally located carbon.
I hope this helps. If there are any problems with this please tell me and I will update it.
This is a very irritating smiley, but I suppose it fits.
