THE MAD RUSH DOWNSTAIRS: FREE ENERGY AS THE DRIVING FORCE BEHIND CHEMICAL REACTIONS
Write out and explain the intuitive meaning of the equation for the free energy change in a chemical reaction,
and draw an accompanying color-coded and labeled graph of the equation. Talk about what drives chemical reactions
inside living cells. Be sure to carefully define all the terms in the equation, and give intuitive explanations of how changing the independent variables in the equation change the "delta G" value and thereby determine whether the
reaction goes forward, backward, or is at equilibrium. Use the hydrolysis of nucleotides in the formation of RNA
and DNA to illustrate the thermodynamic principles that allow cells to run the chemical reactions that sustain life.
At the very end, address the question of whether the chemical reactions occurring inside a living cell are at equilibrium,
or away from equilibrium, and why that has to be the case for life to go on.
Complete hydrolysis of chromosomal nucleic acids gave inorganic phosphate, 2-deoxyribose (a previously unknown sugar) and four different heterocyclic bases (shown in the following diagram). To reflect the unusual sugar component, chromosomal nucleic acids are called deoxyribonucleic acids, abbreviated DNA.