Molecules of Life


Structure of Glucose and Fructose and Functions of carbohydrates

The symbols D and (+) represent the configuration and optical rotation of the molecule respectively. The form of glucose in which the –OH group at C-5, i.e. farthest asymmetric carbon atom from carboxyl carbon, lies on the right, is called as D-glucose and if it lies on the left, the form is called as L-glucose. Glucose is an optically active compound as it possesses four asymmetric carbon atoms or the chiral centers. It may possess two optical isomers, one which rotates the plane-polarized light to the right is called as dextrorotatory and the another which rotates the plane of polarized light to the left is called as levorotatory glucose.


The carbohydrates which do not break down into any simple molecules upon hydrolysis are called as monosaccharides. So, monosaccharides are simplest carbohydrates and represent a complete carbohydrate unit. These may contain 3 to 6 carbons atom in their molecules and can be absorbed directly into the bloodstream of living beings. About 20 monosaccharides occur normally. For example glucose (C6H12O6), galactose, fructose rodpse, glucose etc are some common monosaccharides.

Introduction of biomolecule and Carbohydrate and its function.

The branch of science that deals with the study of the chemical composition of the living organism and also the various chemical changes take place within them is known as biochemistry.The metabolism , biomolecules and biochemical in the presence of the suitable catalyst called enzyme play an important role in the living system for regulation excretion, secretion and for other purposes.The term carbohydrate denotes hydrate of carbon and can be represented as general formula Cx(H2O)y.

The cell and amino acid

The cell is too small to be seen with our own naked eye and it can be seen with the help of the microscope. It is the fundamental unit of life.A living cell is composed of about 50 elements and the 11 elements are the most abundant element. They are O, C, H, N, Ca, P , K, S, Cl, Na, and Mg.At physiological P.H both amino acid group and carboxylic group of amino acid are ionised. Therefore, in the cell, all amino acids exist as an ionizable molecule

Protein and its types.

Protein is the polymer of amino acids.They are essential for growth and maintenance of life. They are high molecular weight and contains nitrogen agent as an essential element. On hydrolysis, they give amino acid.When protein is denatured, its secondary and tertiary structure are destroyed due to the cleavage of non-covalent weak bonds like H-Bond, ionic interaction, van der wall interaction. The primary structure of the protein is most important and the change in the amino acid in the sequence causes to change in the biological activities.

Nucleic acid

Nucleic acid constitutes an important class of biomolecule which are found in all living cells except the red blood cells of the mammal. They are present in the cells in the form of nucleoproteins ( the proteins containing nucleic acid as non-proteinous part).The commonly found purines are adenine (A) and guanine (G).The commonly found pyrimidines are thymine (T), Cytosine and Uracil (U) etc.

Enzymes and Lipid

Enzymes are the important group of globular proteins which acts as a biological catalyst that catalyses biochemical reactions in the living organism.Soap is sodium or potassium salts of some long chain fatty acids . Sodium salts of fatty acids are known as hard soap whereas potassium salts of fatty acids are known as soft soaps.Saponification is the process of hydrolysis of fat in alkaline medium (i,e with NaOH or KOH) to give alcohol and sodium or potassium salts of carboxylic acids of higher fatty acids is known as saponification process.