Peptide bonds are synthesized through a dehydration reaction where the carboxyl group of one amino acid reacts with the amino group of another, releasing a water molecule.
Here's a breakdown of the process:
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The Reactants: Peptide bond formation involves two amino acids. Each amino acid has an amino group (-NH2) and a carboxyl group (-COOH).
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The Reaction: The carboxyl group of one amino acid reacts with the amino group of the other. Specifically, the oxygen atom from the carboxyl group (-COOH) and two hydrogen atoms from the amino group (-NH2) are removed as a water molecule (H2O).
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Peptide Bond Formation: The carbon atom from the carboxyl group now forms a covalent bond with the nitrogen atom from the amino group. This covalent bond is called a peptide bond (also known as an amide bond).
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Dehydration: Because a water molecule is removed during the formation of the peptide bond, the process is called a dehydration reaction (also known as a condensation reaction).
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Repeating the Process: This process can be repeated with additional amino acids to create longer chains called peptides or polypeptides.
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Directionality: While protein biosynthesis naturally proceeds from the N-terminus to the C-terminus, in vitro peptide synthesis most often occurs by coupling the carboxyl group of the incoming amino acid to the N-terminus of the growing peptide chain (C-to-N synthesis).
In summary, peptide bond synthesis involves a dehydration reaction between the carboxyl group of one amino acid and the amino group of another, creating a covalent bond and releasing a water molecule. This process links amino acids together to form peptides and proteins.
