Dehydration synthesis is a chemical reaction where a molecule of water is removed from two monomers, joining them together to form a larger polymer.
Here's how it works:
* Polypeptides: Amino acids are joined together by peptide bonds, formed through dehydration synthesis. The hydroxyl group (-OH) from one amino acid and a hydrogen atom (-H) from another are removed, forming a molecule of water and leaving a covalent bond between the two amino acids.
* Starch: Glucose monomers are joined together by glycosidic bonds, also formed through dehydration synthesis. The hydroxyl group (-OH) from one glucose molecule and a hydrogen atom (-H) from another are removed, forming water and leaving a covalent bond between the two glucose molecules.
Key features of dehydration synthesis:
* Water is removed: This is the defining characteristic of dehydration synthesis.
* Monomers join to form polymers: Small subunits (monomers) are linked together to create larger molecules (polymers).
* Energy is required: Dehydration synthesis is an endergonic reaction, meaning it requires energy input.
Example:
In the synthesis of a polypeptide, two amino acids, glycine (Gly) and alanine (Ala), are joined together:
* Glycine + Alanine -> Gly-Ala + H₂O
Here, the removal of a water molecule allows the formation of a peptide bond between glycine and alanine, creating a dipeptide.
