macromolecules of life
MACROMOLECULES OF LIFE DEFINITIONS INORGANIC CHEMISTRY A branch of chemistry which studies the structures, synthesis and reactions of compounds other than HYPERLINK http//searchbox.hyperdictionary.com/dictionary/hydrocarbons t _blank hydrocarbons and their derivatives ORGANIC CHEMISTRY A branch of chemistry that deals specifically with the structures, synthesis and reactions of carbon-containing compounds. CHEMICAL BONDS When two or more atoms are bonded together to form new and more complex aggregates the force of attraction that holds them together is called a chemical bond. IONIC BONDS The bond in which a complete transfer of an electron from one atom to another and the mutual attraction of the two ions thus formed is termed an ionic bond. Best example is NaCl or the table salt. COVALENT BONDS If the electron is shared between two atoms and keeps them together, this type of a bond is called covalent bonds. Good examples are H2O, H2, N2, O2, CH4 . Organic compounds are based on the element CARBON (Atomic 6) which has a covalent bonding capacity of 4. Carbon is present in an enormous number of known chemical compounds of all the elements, only Hydrogen has more compounds. Although Carbon can and does bond to a variety of different elements, it is most commonly bonded to Hydrogen, Oxygen, Nitrogen or more Carbon. Of central importance in organic chemistry are the compounds containing only C and H, which are called HYDROCARBONS and the number of compounds of this kind is immense. A basic reason for the great variety of hydrocarbons is the readiness with which C to C bonds can form, producing chains of varying lengths and shapes. Therefore classification of hydrocarbons is necessary (see CHAPTERII.PPT file Slides 2, 3, 4). There are three types of molecular formulas that are used to represent hydrocarbons. i) Molecular Formulas ii) Condensed structural formulas and iii) Structural formulas (Slide 5). As the number of carbon atoms increase, the more different