hese molecules are usually produced in the body of living organisms, but can also be synthetized in the laboratory also. 

There are two types of molecules, organic and inorganic. The organic molecules are thé molecules which contain carbon as basic element, bonded with hydron atoms. 

The inorganic molecules do not contain carbon as basic element or hydrogen ts not directly bonded with carbon. 

(1) Formation of Large Molecules: ) 

The molecules in the body of living organisms are usually larger in size, catled macromolecules, also known as polymers. These are formed by the combination of smalier molecules, called micro molecules, also known as monomers. 

Macromolecules or polymers are of four types: 

(i) Proteins: These are composed of small micromolecules or sub units, called amino acids. 

) Carbohydrates (Polysaccharides); Jhese are formed by the combination of monosaccharides (simple sugars). Lipids: These are formed by the combination of faty-compounds. Nucleotides: These are the sub units of nucleic-acids. The macromolecules are formed by a process, called condensation. When two macromolecules (monomeres) join together, one hydroxy! group (OH) of one monomer 

§ with Hydrogen (H) of another monomer to form water. By releasing water two gether | form a macromolecule. Condensation process heips to attach two compounds to form a larger molecule. This process is, also called dehydration, because removal of water takes place. In this process a proper enzyme is 

used and energy is also required. 

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H — | Monomer |——| OH +H | —Monomer | —OH 

Ly —| Monomer | —Monomer | — OH