Amino Acid Properties and Side Chain Classifications

Vocabulary flashcards generated from lecture notes covering nonpolar, polar, and charged amino acid properties, structures, and mnemonics.

Nonpolar amino acids

A class of nine hydrophobic amino acids whose varying degrees of hydrophobicity are associated with the size and shape of their nonpolar side-chains.

Nonpolar side chains diagram

Diagram depicting the nine nonpolar, hydrophobic amino acids: Glycine (Gly, G), Alanine (Ala, A), Valine (Val, V), Leucine (Leu, L), Isoleucine (Ile, I), Methionine (Met, M), Phenylalanine (Phe, F), Tryptophan (Trp, W), and Proline (Pro, P).

Proline nonpolar character

Proline is classified as nonpolar because its massive hydrocarbon ring overpowers a single, small polar NH group while bonding back to the backbone.

Polar amino acids

A class of six hydrophilic amino acids that contain polar, but uncharged, side-chains.

Polar side chains diagram

Diagram depicting six polar, hydrophilic amino acids: Serine (Ser, S), Threonine (Thr, T), Cysteine (Cys, C), Tyrosine (Tyr, Y), Asparagine (Asn, N), and Glutamine (Gln, Q).

Numbats Can't Quack So They Yelp

A mnemonic used to remember the six polar-uncharged amino acids: N (Asparagine), C (Cysteine), Q (Glutamine), S (Serine), T (Threonine), and Y (Tyrosine).

Cysteine classification

Because cysteine is only weakly polar, it is sometimes classified as a nonpolar amino acid.

Charged amino acids

A class of five hydrophilic amino acids containing polar, electrically charged side-chains.

Every Dang Koala Has Rights

A mnemonic for remembering the charged amino acids and their electrical charges: Negative (E - Glutamic acid), Negative (D - Aspartic acid), Positive (K - Lysine), Positive (H - Histidine), and Positive (R - Arginine).

Acidic amino acids

Hydrophilic, negatively charged amino acids comprising Aspartic acid (Asp or D) and Glutamic acid (Glu or E).

Basic amino acids

Hydrophilic, positively charged amino acids comprising Lysine (Lys or K), Arginine (Arg or R), and Histidine (His or H).

Electrically charged side chains diagram

Diagram illustrating the five electrically charged hydrophilic amino acids, categorized as Acidic (negatively charged) and Basic (positively charged).