Carbohydrates

• Monomer: The smaller units from which larger molecules are made

  
• Polymer: Molecules made from a large

  number of monomers joined together.

  
• Disaccharide:

  • Formed by the condensation of two monosaccharides
  • held together by a glycosidic bond
  • e.g. maltose, sucrose, lactose

  
• Polysaccharide:

  • Formed by the condensation of many glucose units
  • held by glycosidic bonds

  
• Starch:

  • Polysaccharide in plants formed by the condensation of α-glucose
  • contains two polymers - amylose and amylopectin

  
• Glycosidic bond:

  • C–O–C link between two sugar molecules
  • formed by a condensation reaction
  • it is a covalent bond
• Amylose:

  Polysaccharide in starch

  made of α-glucose

  joined by 1,4 -glycosidic bonds

  coils to form a helix

  
• Amylopectin:

  Polysaccharide in starch

  made of α-glucose

  joined by 1,4 and 1,6 glycosidic bonds

  branched structure

  
• Condensation reaction:

  • A reaction that joins two molecules together
  • with the formation of a chemical bond
  • involves the elimination of a molecule of water
• Hydrolysis reaction:

  • A reaction that breaks a chemical bond
  • between two molecules
  • involves the use of a water molecule
• Galactose: An example of a monosaccharide that forms lactose
• Fructose: An example of a monosaccharide that forms sucrose
• Isomer:

  • Molecules with the same molecular formula
  • but the atoms are arranged differently
• Maltose:

  • Disaccharide
  • formed by the condensation
  • of two glucose molecules

  
• Lactose:

  • Disaccharide
  • formed by the condensation
  • of a glucose molecule and a galactose molecule