In During translation, the series of an mRNA molecule is examined from its 5' end by ribosomes that then synthesize an appropriate polypeptide. Together in prokaryotes and in eukaryotes the DNA sequence of a one gene is collinear with the amino acid series of the polypeptide it encodes. Alternatively, the nucleotide series of the coding DNA strand, 5' to 3', specifies in specifically the same order the amino acid sequence of the encoded polypeptide N-terminal to C-terminal. The relationship between the nucleotide sequence of the mRNA and the amino acid series of the polypeptide is called as the genetic code.