1.13 Disaccharides

• • Structurally made of 2 D-glucose units, one of which must be α-D-glucose, linked via an α(1🡪4) glycosidic linkage
  • Digested easily by humans because of an enzyme that can break α(1🡪4) linkages 
  • Baby foods are rich in these.

  A) Maltose

  
• • Produced as an intermediate in the hydrolysis of the polysaccharide cellulose.
  • Cannot be digested by humans.

  A) Cellobiose

  
• • Made up of β-D-galactose unit and a D-glucose unit joined by a β(1🡪4) glycosidic linkage
  • Milk is rich in this disaccharide

  A) Lactose

  
• Lactose intolerance

  a condition in which people lack the enzyme lactase needed to hydrolyze lactose to galactose and glucose
• Lactase

  • Enzyme that hydrolyzes lactose to galactose and glucose
• • Table sugar
  • The most abundant of all disaccharides and found in plants 
  • Produced commercially from the juice of sugar cane and sugar beets

  A) Sucrose