Condensation reactions join smaller molecules by covalent bonds while releasing water, forming biological macromolecules such as polysaccharides, peptides and triglycerides.
Coverage 2020–2025 · Updated 15 Jul 2026
A condensation reaction links monomers with a new covalent bond while an H and an OH are removed to form water.
Repeating condensation builds macromolecules: monosaccharides form polysaccharides through glycosidic bonds, amino acids form polypeptides through peptide bonds, and nucleotides form nucleic acids through phosphodiester bonds.
For each step identify the two reacting groups, the new covalent bond and the water released. Polymerization repeats the same bond-forming logic many times, although not every biological macromolecule is a polymer.
When two monosaccharides condense, one supplies H and the other OH; water is released and the remaining atoms are joined by a glycosidic bond.
Condensation is not merely mixing monomers. A covalent bond must form and water must be produced; hydrolysis is the reverse bond-breaking reaction.
This objective is assessed through structured response, commonly using Outline / State / Identify.
Outline / State / Identify
Build the answer around this relationship: Condensation reactions build larger molecules from smaller subunits.
Reversing condensation and hydrolysis in reaction equations.
Representative question
Outline the production of a dipeptide by a condensation reaction, showing the structure of a generalized dipeptide.
B1.1 becomes easy when every answer follows structure -> property -> function. Carbon skeletons and functional groups create molecular diversity. Condensation builds larger molecules and hydrolysis breaks them. Alpha-glucose stores energy as starch and glycogen; beta-glucose forms strong cellulose. Surface carbohydrates enable recognition. Lipids are hydrophobic, triglycerides store energy, phospholipids self-assemble into bilayers, and steroids cross membranes because they are mostly non-polar.
