B1.1.2

• Macromolecules are molecules composed of a very Large number of atoms.
• The main classes of macromolecules are polysaccharides, polypeptides and nucleic acids.
• The subunits of a macromolecule are monomers and the chain is a polymer.
• A condensation reaction links monomers to form polymers.
• To construct macromolecules by condensation, energy is required which is supplied by ATP.
• disaccharide = 2 monosaccharides

  polysaccharide = more than 2 monosaccharides
• Glucose is a monosaccharide that forms glycogen, starch and cellulose (polysaccharide).
• Glucose molecules are linked up with glycosidic bonds. These linkages are formed by condensation using hydroxyl groups.

  
• Condensation reaction: a reaction where two molecules are joined together with a covalent bonds, forming a larger molecule and realising one molecule of water