Makromolekul

Makromolekul, or macromolecule, is a very large molecule with high molecular weight, typically built from many repeating subunits called monomers and joined by covalent bonds in a process known as polymerization. Natural examples include DNA, proteins (polypeptides), and polysaccharides such as starch and cellulose, as well as synthetic polymers like polyethylene and polystyrene.

Makromolecules vary in size, architecture, and properties. They can be linear, branched, or crosslinked to form networks. The physical properties—such as strength, elasticity, solubility, and melting point—depend on molecular weight, the distribution of chain lengths, the chemical composition, and the arrangement of monomer units.

Formation and types: In addition polymerization, monomer units add to reactive ends to build chains. In condensation polymerization, monomers react to form bonds with the elimination of small molecules like water. Copolymerization combines different monomers to yield materials with mixed properties. Crosslinking can further connect chains, creating gels and networks.

Characterization and applications: Macromolecules are characterized by molecular weight and distribution (for example Mw) using techniques such as gel permeation chromatography. They are central to materials science and biology, serving as plastics, fibers, hydrogels, and as biopolymers in living organisms.

In biology, macromolecules perform essential functions: nucleic acids store and transmit information; proteins catalyze reactions and provide structure; polysaccharides store energy and contribute to cell walls and signaling. The study of macromolecules spans chemistry, physics, biology, and engineering.