MCAT - AMINO ACIDS- 52 QUESTIONS FULLY SOLVED & UPDATED 2024

Glycine Glycine is the most simple amino acid - its best to just memorize that this important amino acid has a functional group that only contains a hydrogen! Alanine Alanine has a really simple functional group (just a simple methyl group) that some of the other AA functional groups build on. You can remember the name because the alphabet builds on the letter A and other functional groups build on the simple Alanine R group. What about the other A amino acids? well Alanine has the shortest R group (besides Glycine) so you can remember that it has the shortest name of the amino acids beginning with A! 6 Ways to Show Appreciation for Your Child's Teacher 0:03 / 0:54 Valine This amino acid is the only one that starts with a V and the functional group has a V shape. Leucine You can think of Leucine as a "looser" version of Valine with a slightly longer R-group. Isoleucine Isoleucine is an isomer of Leucine! For those that haven't taken chemistry yet, an isomer is a molecule that has the same chemical formula but a different arrangement of atoms. You can remember which is which because Leucine has a simpler name, and a simpler (less lopsided) arrangement of atoms than isoleucine does. Proline Proline is structurally unique and is often found in turns. Its side chain loops back around and binds with itself, which makes it look like the loop in the letter 'P' for proline. Methionine Methionine has a short 2 carbon chain followed by a sulfur and then a methyl group. You can remember this because the Met is short for methyl, and in chemistry thi indicates the presence of sulfur. Cysteine Cysteine starts with a "ss" sound and it is the only amino acid that makes an S-S bond. In fact, only one other amino acid side chain contains sulfur (methionine) but it is not at the end of the R-group and it cannot form S-S bonds. When you think Cysteine, picture the famous painting in the Sistine chapel of Adam and God Touching fingers! It looks a little like a bond forming that should help you remember that cysteine contains S and is the only amino acid capable of S-S bond formation. Phenylalanine A phenyl group is a hydrocarbon ring. The phenylalanine R group is the alanine R group plus a phenyl. Tryptophan Tryptophan is the chemical that makes you sleepy after eating turkey on Thanksgiving! You can recognize this structure because it has two ring structures that look a little like a turkey. You can also recognize this structure because it is arguably the most complex R group and learning complex R groups might make you sleepy! Tyrosine Tyrosine looks like a phenylalanine with an OH group attached to the phenyl group. You can remember this because the first part of this amino acid name (tyr) kind of sounds like tire which should remind you that the R group contains a tire-shaped phenyl group. Tyr is followed by the letter 'o', which should remind you that an -OH group is attached to the phenyl. Serine Serine is similar to cysteine in structure and in name. The only difference is that the -SH group is swapped out for an -OH group. Here is a mnemonic to help you remember that: OH no a STY! The amino acids that contain an -OH group are serine, threonine, and tyrosine and their one letter abbreviations are S, T, and Y. Threonine You can recognize threonine because it has three things (a hydrogen, a hydroxyl group, and a methyl group) sticking off the carbon of the R group. Aspartate and Glutamate Aspartate and Glutamate are very similar in structure! They both have an R group consisting of a carbon chain ending with a carboxyl group. THe only difference is that aspartate has only 1 C and glutamate has 2 Cs. Here are two ways to remember which is which 1) A comes before G in the alphabet so aspartate is shorter than glutamate. 2) Aspartate has spart in it, which sounds a lot like spartan so it must have fewer Cs. Glutamate has glut in it so it must be greedy and have more Cs. You can tell these amino acids apart from the very similar Glutamine and Arginine amino acids because they end in -ate so they must contain a carboxyl group.