Ribosomal structures of other species in following list. The synthesis of a polypeptide chain occurs catalytically. The already mentioned 'factors' are proteins that are needed for the initiation, elongation and the termination of the polypeptide chain. One to three factors participate in each of these processes. Eucaryotic and procaryotic factors differ fundamentally.
Protein synthesis is a rather energy-consuming process.
Besides ATP is GTP required. A large portion of the energy is used for proof-reading. The newly synthesized peptide starts folding even before it is ready. It develops a secondary and a tertiary structure and achieves thus a thermodynamically favourable state. After synthesis is the chain often modified.