Basic Concept of Biotechnology 23

  Macromolecules and Analytical Techniques      Living organisms are made up of limited number of types of atom viz; carbon, nitrogen, oxygen, phosphorus, sulphur and ions such as sodium, magnesium, chlorine, potassium, calcium and trace elements such as iron, manganese, cobalt, copper, zinc etc. These combine to form various forms of molecules which are building blocks of life. Among which polysaccharides, proteins, lipids and nucleic acids are some of commonly known macromolecules. Many repetitive monomeric units of simpler organic molecules associate to form macromolecules. Carbohydrates act as instant source of energy for living organism whereas lipids act as stored energy. Proteins are involved in functional and structural need of an organism and nucleic acids acts as informational molecules concerned with carrying genetic information and expression of that information. The properties, structure and functional studies of these macromolecules can be revealed...

  Macromolecules Macromolecules are composed of monomeric subunits and these subunits are made up of simple structure. Macromolecules are organic solid matter of the cells and of four types viz: carbohydrates, proteins, lipids and nucleic acids. However the inorganic salts and minerals also constitute a small fraction of the dry weight of the cell.   1.    Carbohydrates. Carbohydrates are polyhydroxy aldehydes or ketones or substances that yield one of these compounds on hydrolysis. They contain hydrogen and oxygen in 2:1 ratio. In plants they will be present in the form of starch and in animals as glycogen. Carbohydrates can be divided into sugars and non sugars. Sugars are crystalline, soluble and most have a sweet taste. Further sugars are divided into mono saccharides and oligosaccharides. Monosaccharide’s are polyhydroxy aldehydes or ketones which cannot be further hydrolysed to yield simpler sugars e.g., glucose, fructose and galactose. Monosaccharides are furt...

  Analytical techniques and applications     The analytical techniques have become the integral part of any research and analysis of biomolecules. The brief description of the analytical techniques is here with discussed.   Centrifugation In 1923 Theodor Svedberg and his student H. Rinde had successfully analyzed large-grained sols by use of centrifugation. Centrifugation is a  process used to separate particles or concentratematerials such as cells, sub cellular organelles, viruses, proteins and nucleic acids suspended in a liquid medium. The object moving in circle at a steady angular velocity will experience a force  F  directed outwards; this is the basis of centrifugation. The centrifugal force generated by a centrifuge is determined by the speed of rotation and the distance of the sample from the axis of rotation. The centrifugal force is usually compared to the force of gravity and is reported as the relative centrifugal force (RCF) in  g ...

  Chromatography Chromatography serves as a means of separation of mixtures and for the isolation and partial description of the components whose presence may be known or to be identified. Chromatography was first employed by the Russian scientist  Mikhail Tsvet  in 1900. He separated chlorophyll II in 1906 by using thin layer chromatography. Like that of centrifugation Chromatography is also of preparative and analytical type. Preparative chromatography is used to separate the components of a mixture for further studies or for purification. Whereas, analytical chromatography is done normally with smaller amounts of material and is for measuring the relative proportions of analytes in a mixture. The concept of partition coefficient is the basic principle of chromatography. In chromatography, the components to be separated are distributed between a stationary phase and themobile phase in which a stationary phase could be paper (paper chromatography), silica (thin layer and...

  Electrophoresis The molecules are separated on the basis of their charge and mass ratio in an electric field or in another words migration of charged ions in an electric field, this is the principle of electrophoresis. Several types of medium are present to perform the electrophoresis procedure  via ; Filter paper which is moistened with buffer and placed between electrodes and by which small molecules, amino acids and nucleotides can be separated. Polyacrylamide gelwhich are covalently cross linked and are casted in tubes or as slabs, they are used to separate proteins and nucleic acids. Agarose gel a highly purified polysaccharide derived from agar (extracted from seeweed), long sugar polymers held together by hydrogen and hydrophobic bonds but with no crosslinks are used to separate very large proteins, nucleic acids and nucleoproteins. Two types of gel electrophoresis include; one dimension and two dimension. One dimension includes SDS-PAGE, Native PAGE and Iso Electric ...

  Spectroscopy Atoms and molecules interact with electromagnetic radiation and may absorb and/or emit Electromagnetic radiation. The patterns of absorption and/or emissions are called ‘ spectra ’. Spectroscopy is concerned with the interpretation of these spectra .  In other words it is a study of interaction between electromagnetic radiation and matter. Different regions of the  electromagnetic spectrum  provide different kinds of information as a result of such interactions. A spectrophotometer is an instrument that measures the amount of light or electromagnetic radiation that is absorbed or emitted by a sample. Arnold J. Beckman at the National Technologies Laboratory (NTL) invented the Beckman DU spectrophotometer in 1940. Some of the electromagnetic wave parameters is useful in understanding the spectroscopy.Wavelength (λ ): Wavelength is the distance between the consecutive peaks or crests and is expressed in nanometers 1nm=10 -8  meters.Frequency (ν): Fr...