Explain how life on earth is dependent on both polarity of covalent chemical bonds and hydrogen bonding. Reference water, proteins and nucleic acids in your answer.
already you have the hints; i.e. water, proteins and nucleic acids. these are the most fundamental of life without these life is not possible.
water contains one oxygen atom and 2 hydrogen atoms in a covalent bond. because of the difference in the atoms electronegativity (oxygen is more), the sharing of electrons is not equal giving oxygen more share of the electron and so it is fairly negative leaving hydrogen fairly positive. this makes a single water molecule (H2O) to be polar and so the molecules can adhere to each other in a bond called hydrogen bond which in natural create liquid water that we and the whole planet use for daily survival.
Protein is formed by 4 distinct structures which are held by hydrogen bond. these are primary, secondary, tertiary and quaternary structures (you can research for this). you will notice that hydrogen bond is also present in the molecule because at some part of the protein, polarity is enhanced by the presence of the NH group (remember proteins are formed by amino acids containing NH group). In order for the protein to function well, the bonds are arranged in a way that will give the specific conformation of the molecule as in enzymes etc..If the bonds (polarity) are not present, proteins and other biomolecules would hardly form.
hydrogen bond is also present in DNA molecules (nucleic acids combined together) giving a spiral structure of the molecule to store millions of genetic codes in a single DNA strands.
Read more on Biochemistry field and you will get more.