How are polypeptides formed?

Polypeptides are formed through the condensation of many amino acids, which is a key process in protein synthesis. This process involves the formation of peptide bonds between amino acids, where a molecule of water is released during the reaction. The condensation reaction combines the amino group of one amino acid with the carboxyl group of another, resulting in the creation of a peptide bond and linking the amino acids together into a growing chain.

This process is fundamental in biology because it constructs the primary structure of proteins, which will fold into specific shapes required for their functions in living organisms. When many amino acids are linked together in this manner, they form polypeptides, which may further fold into functional proteins. Thus, the correct answer highlights the essential chemical reaction that leads to the synthesis of complex proteins in biological systems.