A codon in the genetic code consists of:
A codon is a triplet sequence of bases. The tRNA molecule contains an anticodon. The Shine-Dalgarno sequence is found in the 23S prokaryotic ribosomal RNA. A codon is on the same strand of DNA or mRNA.
One molecule of charged-tRNA
A Shine-Dalgarno sequence
Three consecutive nucleotides
Two complementary base pairs