Core Concepts: Biological Molecules

Core Concepts: Biological Molecules

1. Water

   • Water is a Polar molecule, with a slight electro-negative charge surrounding the Oxygen and and slight electro-positive charges surrounding the Hydrogens.
     • This causes water molecules to be attracted to oppositely charged ions, surrounding the ions and dissociating them from their usual giant ionic lattice. This makes water a useful solvent for polar and ionic substances and a medium for both their transport and chemical reactions involving these substances, such as the formation of Phospholipids using phosphate ions (PO4^-1)
     • This causes water molecules to also be attracted (between the negative oxygen and positive hydrogen ends) to each other forming Hydrogen "bonds". This quality is called Adhesion and is responsible for water's surface tension as well as its liquid state at room temperature.
       • The fact that water can exist as a liquid in temperatures ranging from 0 to 100 degrees celsius makes it useful as a medium for the transport of substances through it, forming the majority of a cell's mass as cytoplasm and being a major constituent to most bodily fluids.
       • The surface tension and adhesion that water exhibits provides it with interesting and highly useful properties for life. For example, due to the process of capillary action the tall columns of water found in trees are able to form or in the case of surface tension certain insects such as pond skaters can move across the surface of bodies of water.