Peptides are short chains of amino acids linked by peptide bonds. They are considered the building blocks of proteins, differing mainly in size; while proteins are typically composed of one or more long polypeptide chains of more than 50 amino acids, peptides are shorter and often contain between 2 and 50 amino acids. Due to their smaller size and specific sequences, peptides can have a wide range of biological functions, making them crucial in biological systems and research.

Peptides play diverse roles in the human body, including acting as hormones, neurotransmitters, growth factors, and antibiotics, thereby influencing many physiological processes. For instance, insulin is a well-known peptide hormone that regulates glucose levels in the blood. Other peptides, such as those found in venom, have evolved to affect the biological systems of other organisms.

In research, peptides have numerous benefits and applications. They are used to study protein structure and function, understanding the mechanisms of diseases at a molecular level, and developing new therapeutic approaches.