Sharing electrons leads to the formation of covalent bonds between atoms and the formation of molecules. Electrons are not always shared equally in covalent bonds. Oxygen and nitrogen are electronegative compared to carbon and hydrogen. Non-covalent forces are important in biological structures. They are involved in energy storage and many metabolic reactions.
Lipids are hydrophobic.
They function in energy storage and membrane structure. Proteins are polymers of amino acid with unique structure and function. DNA and RNA are polymers of nucleotides important in storing and transmitting genetic information. 2.20 and Chapter 2, pages 31-32 for primary functional chemical groups. Polymers are long chains of covalently linked monomers Condensation Reaction .