Peptides are made by joining amino acids together using a special bond called a peptide bond. This bond is formed when the amino group (–NH₂) of one amino acid combines with the carboxyl group (–COOH) of another amino acid, releasing a molecule of water.

Each amino acid has a central carbon atom, surrounded by:

• A hydrogen atom (H)
• An amino group (–NH₂)
• A carboxyl group (–COOH)
• A unique side chain group (called the R group) that gives each amino acid its own characteristics.

Sometimes, these R groups can interfere with the process of joining the amino acids, so they need to be temporarily protected with special chemical groups until the peptide chain is complete.

How are peptides made in a lab?

In laboratories, peptides are typically made using a method called solid-phase peptide synthesis. Here’s how it works:

1. Starting the Process: The first amino acid is attached to a solid support (a resin) to keep it in place, and its amino group is protected.
2. Adding More Amino Acids: The protective group is removed, allowing the next amino acid to be added. This amino acid forms a peptide bond with the first one.
3. Repeating the Process: The process is repeated, adding one amino acid at a time until the entire peptide chain is created.

Once all the amino acids are in place, the peptide is carefully removed from the solid support. A special acid is used to break the bond between the peptide and the solid support, and it also removes any remaining protective groups on the amino acids.

This step-by-step process allows scientists to create peptides with specific sequences of amino acids for use in research, medicine, or other applications.