The start codon (AUG) is on the 5' end of all mRNAs. Each codon attaches to a particular tRNA. 3' end is free and has a base sequence of CCA. There are complimentary bases in tRNA and hydrogen bonds form in four areas. Causes the tRNA to fold and take on a 3 dimensional structure. If it's 2 dimensional shaped, one of the loops contains an exposed anticodon. This specific anticodon pairs with a specific anticodon of mRNA. 20 amino acids, 20 enzymes. ATP energy. Activated amino acid. tRNA delivers amino acid to ribosome to produce polypeptide chain.
tRNAs bring amino acids to the mRNA-ribosomal complexes. Proteins called elongation factors assist in binding the tRNAs to the exposed mRNA codons at the A site. The initiator tRNA moves to the P site. Ribosomes catalyze the formation of peptide bonds between adjacent amino acids.