1.3.1 Amino Acids & the Peptide Bond

Proteins are made up of smaller units called amino acids, which are the monomers of proteins.

Each amino acid contains the following key components:

• An amino group (NH₂)
• A carboxyl group (-COOH)
• A variable R group, which is a side chain that differs in each amino acid and determines its specific properties.

Formation of the Peptide Bond:

• The carboxyl group of one amino acid reacts with the amino group of another, forming a peptide bond.
• This bond links the amino acids together, creating a dipeptide (two amino acids) or a polypeptide (three or more amino acids).
• As more amino acids join, the chain lengthens, eventually forming a protein. Proteins are essential macromolecules that play a wide range of functions in living organisms, from enzymes to structural components. Understanding the basic structure of amino acids and peptide bonds is key to grasping how proteins are built and function.