6. Hydrophobic R groups Fig 3-5 Secondary amino (imino) group

8. Aromatic R groups Fig 3-5 Polarity: Tyr ~ Trp >> Phe Hydroxyl group

10. Polar, uncharged R groups Fig 3-5 Sulfhydryl group Hydroxyl group Amide group

12. Positively charged R groups Fig 3-5 At pH = 7.0 Imidazole group

13. Negatively charged R groups Fig 3-5 At pH = 7.0 = Aspartic acid = Glutamic acid

14. -C-C-CONH 2 -C-CONH 2 -C-COOH -C-C-COOH -H -CH 3 -C-OH -C-SH -C-C-S-C -C-C-C-C-NH 3 + 雙 和 線 環狀線 中央線 南 港 線 中 山 線 西 北 線 Aliphatic Amide Acidic Imino, Circular Basic Sulfur Hydroxy Aromatic 胺基酸地下鐵道圖 Juang RH (2004) BCbasics Leu L P Pro -C-C C N N + -C- -C- -OH -C- N -C-C-C-N-C-N N + = C -C-C-C C -C-C-C C C -C C C C HN C-COOH  -C-C OH Gln Q Asn N Asp D Glu E Phe F Arg R Lys K His H Gly G A A Ala V Val I Ile Y Tyr Ser S Thr T Met M Cys C Trp W Non-polar Polar

15. If only one amino acid (a.a.) begins with a certain letter, that letter is used Cys teine = Cys = C His tidine = His = H I so le ucine = Ile = I Met hionine = Met = M Ser ine = Ser = S Val ine = Val = V Key convention, p. 74

16. If more than one a.a. begins with a certain letter, that letter is assigned to the most commonly occurring one Ala nine = Ala = A Gly cine = Gly = G Leu cine = Leu = L Pro line = Pro = P Thr eonine = Thr = T

17. Phonetically suggestive Asp artic acid (“aspar D ic acid”) = Asp = D Phe nylalanine (“ F enylalanine”) = Phe = F Arg inine (“a R ginine”) = Arg = R Tyr osine (“t Y rosine”) = Tyr = Y Tr y p tophan ( double ring in the molecule) = Trp = W

18. A letter close to the initial is used As paragine (contains N ) = As n = N Glu tamic acid (near D) = Glu = E Gl utami n e (“Q-tamine”) = Gl n = Q Lys ine (near L) = Lys = K

19. THIS IS EASY … GREAT

21. Can you name these amino acids?