Definition of Macromolecules

  • Macromolecules are large complex molecules, such as proteins or nucleic acids, composed of smaller units called monomers.
  • The word “macromolecule” derives from “macro-“, meaning large, and “molecule”, the smallest unit of a compound that retains its chemical properties.

Structure of Macromolecules

  • Macromolecules are formed by repeated linking of monomers through a process called polymerisation.
  • The monomers are bonded together through covalent bonds, resulting in a long, chain-like molecule.
  • Many macromolecules, such as proteins and nucleic acids, have a complex 3D structure that is essential for their function.

Types of Macromolecules

  • There are four main types of biological macromolecules: carbohydrates, proteins, nucleic acids, and lipids.

  • Carbohydrates, like starch or cellulose, are made up of monomers called monosaccharides, such as glucose.

  • Proteins are made up of monomers called amino acids. Proteins are essential for structure, function, and regulation of body’s tissues and organs.

  • Nucleic acids, like DNA and RNA, are made up of monomers called nucleotides that carry genetic information.

  • Lipids are not true polymers as they are made up of glycerol and fatty acids. They include fats, oils, waxes, phospholipids, and steroids.

Properties of Macromolecules

  • Macromolecules generally have high molecular weights and their physical and chemical properties are largely determined by the functional groups they contain.
  • Due to their large size, many macromolecules are not soluble in water.
  • Macromolecules like proteins and nucleic acids play crucial roles in biological processes.
  • Many macromolecules have a complex, specialized structure that allows them to perform their specific tasks within an organism.