A peptide bond is the chemical link that joins one amino acid to the next. It’s the single connection that turns separate building blocks into a peptide or protein. Here’s a simple explainer.
- What it is: a covalent bond between two amino acids.
- How it forms: one amino acid’s acid group joins another’s amine group, releasing a water molecule.
- Why it matters: peptide bonds are what make a chain a peptide.
How a peptide bond forms
Every amino acid has two reactive ends: an amine group (–NH₂) and a carboxylic acid group (–COOH). When two amino acids join, the acid group of one reacts with the amine group of the other. This reaction links them and releases a single water molecule — a process called a condensation reaction.
Why it matters
- It builds the chain: repeat the bond many times and you get a peptide, then a protein.
- It’s stable: peptide bonds are strong, which is part of why peptides hold their shape.
- It defines direction: the chain has two distinct ends — see N-terminus & C-terminus.
For the bigger picture, see Peptides vs Amino Acids and What Are Research Peptides?
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