Biology

Chemical Basis of Life    

• The bodies of all organisms are composed of variety of chemical compounds.
•  These chemical compounds are formed by the bonding of naturally existing elements in different ways.
• There are only about 25 elements in the living body out of the 92 elements present in nature.
•  They are present at different locations in the body in different forms.
• The most common 4 elements in the living body are Carbon, Hydrogen, Oxygen &Nitrogen. 
•  Other than above Sulphur, Phosphorous, Sodium, Potassium, Calcium,Magnesium, Iron and Chlorine are essential for the survival of organisms  
• Chemical compounds that build up living matter can be divided into two categories as organic compounds and inorganic compounds.
• Compounds which containCarbon are known as organic compounds and compounds which do not containCarbon are known as inorganic compounds. 
• Those organic compounds that build up the living body or living matter are known as biological molecules.
• There are four types of biological molecules.
•  They are:
• Carbohydrates
• Proteins
• Lipids
• Nucleic acids