ABSTRACT
The distribution of molecules inside the cell, as well as in its organelles, is not random but well-defined, which makes the very different functions of different cells possible. Molecules in which atoms are symmetrically distributed are nonpolar molecules, and molecules in which atoms are nonsymetrically distributed are polar molecules. The distribution of charges inside the molecule also can be influenced by neighboring molecules. The distance between atoms bound by the van der Waals' forces is decisive for the binding of the reacting molecules, for example binding of antigens by antibodies. Bonds between covalently bounded positively charged hydrogen atoms with covalently bounded negatively charged acceptor atoms are defined as hydrogen bonds. Charged positive or negative groups inside the molecules usually are neutralized by neighboring oppositely charged groups. The reversible combination of oxygen with the hemoglobin molecule is dependent on temperature, ionic strength, pCO2, and pH of the reaction medium.
