CH_{3} \ Valine, C_{5}H_{11}NO_{2}, CH·CHNH_{2}·COOH, / CH_{3} amino-isovalerianic acid. CH_{3} \ Leucine, C_{6}H_{13}NO_{2}, CH·CH_{2}·CHNH_{2}·COOH, / CH_{3} amino-isocaproic acid. CH_{3} \ Isoleucine, C_{6}H_{13}NO_{2}, CH·CHNH_{2}·COOH, / C_{2}H_{5} amino-methylethyl-propionic acid. / \ Phenylalanine, C_{9}H_{11}NO_{2}, | |CH_{2}·CHNH_{2}·COOH, | | phenyl-amino-propionic acid. \ / / \ Tyrosine, C_{9}H_{11}NO_{3}, | |CH_{2}·CHNH_{2}·COOH, OH| | paraoxy-phenylalanine. \ / Cystine, C_{6}H_{12}N_{2}O_{4}S_{2}, HOOC·CHNH_{2}·CH_{2}S-SH_{2}C· CHNH_{2}·COOH, di(thio-amino-propionic acid). B. Monoamino-dicarboxylic acids: Aspartic acid, C_{4}H_{7}NO_{4}, HOOC·CH_{2}·CHNH_{2}·COOH, amino-succinic acid. Glutamic acid, C_{5}H_{9}NO_{4}, HOOC·CH_{2}·CH_{2}·CHNH_{2}·COOH, amino-glutaric acid. C. Diamino-monocarboxylic acids: Ornithine, C_{5}H_{12}N_{2}O_{2}, H_{2}N·CH_{2}·CH_{2}·CH_{2}·CHNH_{2}·COOH, di-amino-valerianic acid. Lysine, C_{6}H_{14}N_{2}O_{2}, H_{2}N·CH_{2}·CH_{2}·CH_{2}·CH_{2}·CHNH_{2}·COOH, di-amino-caproic acid. Arginine, C_{6}H_{14}N_{4}O_{2}, NH_{2} / HN=C \ NH·CH_{2}·CH_{2}·CH_{2}·CHNH_{2}·COOH, guanidine-amino-valerianic acid. Di-amino-oxysebacic acid, C_{11}H_{12}N_{2}O_{3}. Di-amino-trioxydodecanic acid, C_{12}H_{26}N_{2}O_{3}. D. Monoimido-monocarboxylic acids: Proline, C_{5}H_{9}NO_{2}, H_{2}C---CH_{2} | | H_{2}C CH·COOH, pyrrolidine-carboxylic \ / acid N | H Oxyproline, C_{5}H_{9}NO_{3}, proline with one (OH) group. E. Monoimido-monoamino-monocarboxylic acids.