Amino Acids and Functional Groups

Nonpolar side chains; hydrophobic

Glycine, alanine, valine, leucine, isoleucine, methionine, phenylalanine, trytophan, proline

Polar side chains; hydrophillic

serine, threonine, cysteine, tyrosine, asparagine, glutamine

Electrically charged side chains; hydrophillic

Acidic (negatively charged): aspartic acid, glutamic acid

Basic (positively charged): lysine, arginine, histidine

Glycine

Gly or G

Nonpolar

Ala or A

Nonpolar

Alanine

Val or V

Nonpolar

Valine

Leu or L

Nonpolar

Leucine

Ile or I

Nonpolar

Or H3C---CH instead of H--C--CH3

Isoleucine

Met or M

Nonpolar

Methionine

Phe or F

Nonpolar

Phenylalanine

Trp or W

Nonpolar

Tryptophan

Pro or P

Nonpolar

Proline

Ser or S

Polar

Or OH---CH2 instead of CH2OH

Serine

Thr or T

Polar

Threonine

Cys or C

Polar

Cysteine

Tyr or Y

Polar

Tyrosine

Asn or N

Polar

Asparagine

Gln or Q

Polar

Glutamine

Asp or D

Acidic (negatively charged)

Aspartic acid

Glu or E

Acidic (negatively charged)

Glutamic acid

Lys or K

Basic (positively charged)

Lysine

Arg or R

Basic (positively charged)

Arginine

His or H

Basic (positively charged)

Histidine

(--OH)

Alcohols

Polar

Hydrogen bonding

Hydroxyl Group

(C==O)

Aldehydes: attached at end of carbon skeleton

Ketones: in the middle of carbon skeleton

Carbonyl group

(--COOH)

Carboxylic acids, or organic acids

very acidic

H atom can easily dissociate

Carboxyl Group

(--NH2)

Amines

tend to act as base

gain H from surrounding solution

Amino Group

(--SH)

thiols

important in protein structure (tertiary structure)

two --SH groups can react forming a "cross-link" that helps stabilize protein structure

Sulfhydryl Group

(--OPO3(2-))

Organic phosphates

contributes negative charge (1- when positioned IN chain of phosphates, and 2- when positioned at END)

Phosphate Group

(--CH3)

methylated compounds

affects expression of genes when on DNA or proteins bound to DNA

affects shape and function of male and female sex hormones

Methyl Group