遗传密码 Second letter U C G I UUU Phenyl LUAU UGU UUC alanine UCC UAC Tyrosine UGC Cysteine c U U Serine UUA Leucine UCG AA Stop codon Stop codon UUG UAG Stop codon] G CUU CCU CAU g c CUC CCC CAC Histidine CGU Leucine CUA CAROline CGA/ C CGO CUG AUU ACU AUC Isoleucine ACO AACAsparagine AGC Serine C AUA Methionine: ACA/Threonine AAA AGA AuG initiation ACG AAG-ysine AGG Arginine codon GUU GCU GAU Aspartic GUC GAC acid G GCC GUA Valine GCA Alanine GCG GAA GGAGlycine GUG GAG Glutamic GGG GUcAG acid遗传密码