Disaccharides, Biology

DISACCHARIDES

  • They are oligosaccharides composed of two monosaccharide residues .
  • Three common disaccharides are   sucrose (glucose + fructose) = cane suger maltose (glucose + glucose) = malt sugar lactose (glucose + galactose) = milk sugar
  • Common formula is Cn(H2O)n-1.

SUCROSE

  • Commercial or Table sugar.
  • Obtained from stems of Sugarcane (Saccharum officinarum) and roots of Beet sugar (Beta vulgaris).
  • Sucrose is a non-reducing sugar.
  • Sweetness index of sucrose is 100.
  • Formed of two molecules each of glucose and fructose.
  • It has neither aldehyde group nor keto group.

MALTOSE

  • Malt Sugar
  • It is a disaccharide formed of two molecules of glucose which are connected to each other through the a -1, 4 D-glycosidic linkage.
  • It is present in Barley.
  • Maltose is formed during hydrolysis of starch.
  • It is found in germinating cereals.
  • The sugar is present in malt, and is therefore, also called malt sugar.
  • Sweetness index is 30.
  • Maltose is a reducing surgar.

LACTOSE

  • Milk Sugar.
  • It is a disaccharide sugar present in milk upto the extent of 5%.
  • Lactose is formed of D-galactose and D-glucose, both in pyranose state, through the b-1, 4 glycocydic bond.
  • The monosaccharide galactose is also synthesised from glucose inside the mammary glands.
  • Sweetness index of lactose is 16.
  • Like maltose, lactose is a reducing sugar.
  • Souring of milk occurs when bacteria convert lactose into lactic acid.
  • Present only in mammals.

TREHALOSE

  • It is a disaccharide sugar made of two glucose residues which was originally obtained from cocoon of Trehela (weevil Larinus species) as sweetening agent.
  • Trehalose is found in haemolymph of some insects and fungi including yeast.
Posted Date: 10/9/2012 3:37:03 AM | Location : United States







Related Discussions:- Disaccharides, Assignment Help, Ask Question on Disaccharides, Get Answer, Expert's Help, Disaccharides Discussions

Write discussion on Disaccharides
Your posts are moderated
Related Questions
FUNCTIO N OF LIPIDS Fats are storage products of both plants and animals. I n plants , fats are commonly stored in spores and seeds while in animals they are sto

Crisis due to Deforestation Due to continuing deforestation we are faced with a major ecological and socio-economic crisis. To reverse this trend of deforestation a National

Which of Mendel's postulates can only be demonstrated in crosses involving at least two pairs of traits? a) Segregation b) dominance/recessiveness c) independent assortment d) unit

D-glucose differs from D-galactose only in the arrangement around carbon 4. Therefore D-glucose and D-galactose are- Select one: a. enantiomers b. epimers c. mirror ima

Describe the Biological parameters of living organisms Biological parameters which include living organisms constitute an important component of soil.  Even though organisms fo

Explain the Carbohydrates and Fat Requirements during Sepsis? Carbohydrates should constitute nearly 60% to 70% of the total energy. Glucose is the primary calorie substrate in

Phylum platyhelminthes (13,000 species Flatworm) The body is flattened. Gastrovascular cavity is branched, dense bodies with many cell layers, mouth but no anus. Hermaphrodite

Fire and Cookery : Fire and Cookery where and when fiie came to be used  is not known.  Fire, to start with, must have been a frightening thing, giving rise to many myths and l

Psychological Problems Failure to fulfill the patient's expectations and failure to gain the patient's acceptance and satisfaction constitutes a psychological failure. It is hi

What is the meaning of Body composition? It refers primarily to the distribution of muscle, fat, bone and other tissues in the body, and its measurement is often considered as