Proteins Biopolymers of a-amino acids. -Amino acids are joined by peptide bond. They serve a variety of functions: ■Structure Enzymes Transport Protection ■Hormones Chapter 24 2 Chapter 24 2 Proteins ▪ Biopolymers of -amino acids. ▪ Amino acids are joined by peptide bond. ▪ They serve a variety of functions: ▪ Structure ▪ Enzymes ▪ Transport ▪ Protection ▪ Hormones