2. Genetic code and ribosomes

Figure 10

Figure: 10

 Figure 11

Figure: 11

2.2 Transfert RNA (tRNA)

As there is no direct contact (thus no molecular recognition) between the bases of the codon on mRNA and the corresponding amino acid, an intermediary molecule is therefore needed: tRNA.

Structure of tRNA

  • 3D structure: tRNA is « L » shaped (figure 10)

  • 2D structure: tRNA is a 4-stemmed structure resembling a cloverleaf (figure 11).

    • The stem, containing the 3' end, binds the amino acid.

    • The opposite loop, called the anticodon loop, is the position where mRNA and tRNA are linked.