CHAPTER 13: BIOCHEMISTRY

Major Topics

Student will be able to :

  • Distinguish between mono-,di-and trisaccharides.
  • Describe the bonding in a protein molecule.
  • Explain the sources and uses of carbohydrates, proteins, and lipids.
  • Differentiate between fats and oils.
  • Describe the importance of nucleic acids.
  • Define and explain vitamins and their importance.

Life requires energy. Where this energy comes from? Can you use the energy of sun light directly to perform all life activities? Plants trap this energy and convert it into chemical energy. How? They store this energy in substances such as carbohydrates, proteins and lipids. We need these compounds for existence. For proper nutrition, our diet should include balanced proportions of carbohydrates, proteins and lipids. We also need adequate amount of vitamins, minerals and fibre.

Some compounds found in every living cell, serve as the information and control centers of the cell. They have ability to reproduce, store and transmit genetic information. What are these compounds? This chapter will enable you to recognize these important compounds.

Society, technology and Science

5%m/v aqueous solution of dextrose is used in drips. 5% m/v aqueous solution means 5 grams of dextrose dissolved in water to form 100 cm3 of solution. It is intravenously given to patient who is severely dehydrated or is unable to eat or is not allowed to eat.

Enzymes are large protein molecules. They are biological catalysts. They catalyze chemical reactions in living organisms. Enzymes are also commercially important. They are used in the production of sweeteners, chocolate syrup, bakery products, infant foods, detergents to remove food stains, in cheese making, in paper and pulp industries to remove sticky matter, to prepare fabrics for clothes, furniture, and other household items. For example (a) enzymes like diastase, invertase, and zymase are used in the fermentation of molasses and starch to produce ethanol. (b) Amylase is used in bread making. (c) Proteases and amylase are used in detergents to remove food stains on the cloths. (d) Lactase is used in infant foods.