• Biomolecule is also known as biological molecules.
  • It is the harmonious and synchronous progress of chemical reaction in body which leads to life.
  • Mostly these organic compounds which build-up the living system also responsible from their growth and maintenance.
  • The sequence which is relates Biomolecule to the living organism is







  • Living system which are made up of multiple complex biomolecules like carbohydrate, nucleic acid, lipids, proteins etc.
  • These are essential constituent in our food mostly proteins and carbohydrates.
  • Biomolecules interact with each other and proceed constitute the molecular logic of life processes.
  • Some of the simple molecules which is like minerals and vitamins also plays an important role in function of the organism.


  • Carbohydrates are primarily produced by plants and form a very large group of naturally occurring organic compounds.
  • Also these are the active polyhydroxy aldehyde or ketones or compounds by hydrolysis which give these units know as saccharides.
  • The general formula of carbohydrate is Cx(H2O)y
  • A huge number of their reaction has shown that they always Contain a specific group.
  • These are also called sugar cause It’s sweet in taste.


  • Depending upon the carbohydrates behaviour towards hydrolysis ,carbohydrates are devided in to following 3 types.
  • Monosaccharide
  • Oligosaccharides
  • Polysaccharides
  • Monosaccharides are further classified on the basis of the no of atoms it have and also the functional group present in this.
  • Basically it’s a carbohydrate that can be hydrolysed further to give simpler unit of polyhydroxy aldehyde or ketone which is known as monosaccharides.
  • Monosaccharides which contain aldehyde group is known as aldose and contain keto group is known as ketose.
  • Some of the common example are glucose, fructose, ribose etc.
  • The no of carbon atoms present in monosaccharides is also introduced in the name.


(  Different types of monosaccharides)

  • Glucose occurs freely in nature as well as in the combined form.
  • Mostly glucose is present in sweet fruits, honey etc.


  • From sucrose (cane sugar): Sucrose is boiled with dilute hcl or h2so4 in alcoholic solution,glucose and fructose are obtained in equal amounts.
  • From starch: hydrolysis of starch



  • Glucose is an aldohexose which is known as dextrose.
  • This is the monomer of many carbohydrates like starch and cellulose.
  • Molecular formula: The molecular formula of glucose has been found to be C6H12O6.
  • straight chain structure: when aqueous solution of glucose is treated with sodium. amalgam or sodium borohydride, it is reduced to sorbitol a hexahydric alcohol.


  • Heating with hydriodic acid and red phosphorus at 100 °C  give a mixture of n-hexane and 2- iodohexane.
  • The formation of n-hexane suggest that all the six carbon atoms in glucose are arranged in a straight chain structure of glucose.


  • Chain structure of glucose explained most of it’s properties but some of the reaction and facts couldn’t be explained by this structure.
  • Despite having the aldehyde group , glucose doesn’t give Schiff’s test and it doesn’t form the hydrogensulphite addition product with sodiumbisulphate.
  • The pentaacetate of glucose doesn’t react with hydroxylamine indicating the absence of free CHO group.


These behaviour couldn’t explain by the open chain structure so for that cyclic chain is needed.

  • Disaccharides are basically the sugar which is formed when two monosaccharides are joined by glycosidic linkage.
  • The three most common example which is sucrose maltose and lactose.
  • Disaccharides are basically one chemical grouping of carbohydrates.
  • The general formula of disaccharides are c12 h22 o11.
  • The joining of simple sugars into double sugar only happens when condensation reaction happens which involves the elimination of a water molecule from the functional groups.
  • the disaccharides by the hydrolysis process with dilute acid or enzyme yield two molecules eather in the same monosaccharides or different.
  • In the disaccharide if the reducing sugars as example aldehyde or ketone group are bonded which is known as non reducing sugars eg sucrose.
  • Those sugars in which these fictional group are free, are known as reducing sugar. ex- maltose and lactose.
  • sucrose-it is one of the most common Disaccharide is sucrose which give D-(+) glucose and D(-) fructose on hydrolysis.


D-glucose                   D-fructose

  • Polysaccharide which contain a large number of monosaccharide units and they are joined by glycosidic linkage.
  • Basic function of these polysaccharides are food storage and structural material.
  • Ex- starch, cellulose, glycogen etc.


  • Basically starch is the main storage polysaccharide of plants as well as the one of the most important dietary source for human being.
  • It’s a polymer of Alpha glucose and contain two components which is amylose and amylopectin.
  • Amylose is consist of 15 to 20% of starch and amylopectin is consist of 80 to 85% of starch.
  • Basically it’s branched chain polymer of alpha d glucose units in which chain is formed bye C1 C4 glycosidic linkage where branching occurs by c1-c6 glycosidic linkage.





  • Carbohydrates are basically the most abundant organic molecule in nature.
  • The major function is source and storage of energy example glucose and glycogen.
  • Also it involves in interaction of the cell.
  • A derivative of carbohydrate is the water soluble vitamin which is ascorbic acid.


  • Basically proteins are the most abundant biomolecules of the living system and the sources of protein is milk, cheese, pulses, peanuts, fish meat etc.
  • It occurs every part in our body and form the fundamental basis structure and functions of life.
  • All the proteins are polymer of Alpha amino acid.


  • amino acids contain amino and carboxylic groups.
  • mainly depending upon the relative position of amino group with respect to carboxyl group the amino acid get divided into Alpha, beta, gamma and theta.
    All alpha amino acid has a name which usually reflect its property of the source or the compound.
  • Amino acids are basically devided into acidic, basic and neutral based on the


1)R group

2)polarity and R group

3) Distribution in Protein

4) Nutritional requirement

5) Number of amino and carboxylic group


  • Proteins are the polymer of Alpha in amino acid and also the connected to each other by peptide bond or peptide linkage.
  • Basically peptide linkage is an amide formed between COOH group and NH2 group by this reaction between two molecules of amino acid process through the combination of amino group of one molecule with carboxylic group of the other.
  • By this the elimination of water happens and formed a peptide bond -CO-NH- also the product is known as dipeptide cause it made up of two amino acid.
  • Protein is classified into two types on the basis of their molecular shape.

Fibrous protein: when the polypeptide •chains are held together by hydrogen bond or disulphide bond and run parallel then fibre like structure is formed.

  • Ex-keratin, Myosin

Globular proteins

  • This kind of structure results when the chain of polypeptides coil around to give a spherical shape.
  • Ex-Insulin and albumins
  • Structure and shape of proteins is divided into four types:

Primary structure of protein

  • Proteins have one or more polypeptide chain.
  • Each polypeptide in a protein has amino acid linked with each other in a specific sequence also it is the sequence of amino acid that is said to be the primary structure of that protein.

Secondary structure of protein

  • Specifically it refers to the shape in which long polypeptide chain can exist also they are found to exist in two different types of structure which is alpha helix and beta pleated sheet structure.
  • in Alpha helix a polypeptide chain forms all possible hydrogen bonds by twisting into right handed screw with the NH group of is amino acid residue hydrogen bonded to the C=O of an adjacent turn of the helix.
  • In beta pleated sheet structure all peptide synthesis Trek route to nearly maximum Extension and after that led side by side which are held together by intermolecular hydrogen bonds the structure resembles the treated faults of drapery and therefore is known as beta pleated sheet.

Tertiary structure of protein

  • It represents overall folding of the polypeptide chains.
  • By the further folding of the secondary structure it gives rise to two molecular shape switches fibrous and globular.

Quaternary structure of protein

  • Proteins which are composed of two or more polypeptide chain referred to as subunits.
  • The special arrangement of the subunit it is known as quaternary structure of protein.



  • Life is quite impossible without chemical reaction in living organism as example digestion of food.
  • it consists of various chemical reaction. These are orcas with the help of certain biocatalyst which is known as enzymes.
  • Enzymes are generally named after the compounds are the class of compounds of on which they worked as example enzyme that catalyse hydrolysis of maltose into glucose is named as Maltase.


  • Small quantities of enzyme are needed for the progress of a reaction.
  • As similar to the action of chemical fertilizers enzyme are said to reduce the magnitude of activation energy as example activation energy for acid hydrolysis of sucrose is 6.22 kg mol.


  • Absence of certain organic compound in our diet causes specific diseases. These are known as vitamins.
  • Mostly vitamins can not synthesized in our body plant can synthesise almost all of them so they considered as essential food factor.
  • Different type of vitamins belong to different type of chemical classes it is quite difficult to explain them on the basis of structure.
  • The basic function of vitamins are to perform specific biological function for normal maintenance of optimum growth and health of the organism.


  • Vitamins are get divided into two groups depend upon the solubility in water or fat.
  • Fat soluble vitamins which are soluble in in fat or oil but insoluble in water are kept in this group.
  • water soluble vitamins are that kind of vitamin in which b group vitamins and vitamin C are soluble in water and they are grouped together.


                 NUCLEIC ACID

  • It has been observed that nucleus of a living cell is responsible for this transmission of inheritance characters which is also known as heredity.
  • Chromosomes which are made up of proteins and another type of biomolecules is known as nucleic acid.
  • these are up two types one is deoxyribonucleic acid and another one is ribonucleic acid.


  • DNA contain four bases which is adenine, guanine, cytosine and thymine .
  • RNA also contain four bases ,the first three bases are same but the fourth one is uracil.






  • Hormones are the molecule which is at the intracellular messenger.
  • Basically these are produced by the endocrine gland in the body and four directly into the blood also stream which transport them to the site of action.
  • Hormones do several functions in our body. The basic function is to help to maintain the balance of biological activities in our body.
  • some of these are steroid as example estrogen and androgen. Some are polypeptide as example insulin.
  • growth hormones and sex hormones play role in growth and development.
  • Hormones released by gonads are responsible for development of secondary sex characters. Testosterone is the major sex hormone produced in males.
  • testosterone is responsible for development of secondary male characteristics which is deep boys facial hair general physical constitution.
  • Estrogen is the main female sex hormone It is responsible for development of secondary female characteristics and participate in the control of menstrual cycle.
  • Progesterone is responsible for preparing the uterus for implantation of fertilised egg.