BIO 121 Chapter 3: Energy Catalysis and Biosynthesis Ch3
Document Summary
First law of thermodynamics: energy cannot be created or destroyed (but converted) Second law of thermodynamics: systems will change spontaneously toward those arrangements that have the greatest probability. Biological order is made possible by the release of heat energy from cells moves towards disorder/entropy. When an animal cells breaks down food, energy in the chemical bonds of food molecules is converted into the thermal motion of molecules (heat energy) Hydrogenation = reductions //// dehydrogenation = oxidation. Chemical reactions proceed in the direction that causes a loss of free energy. Cells manage energy by energy coupling use of exergonic process to drive endergonic one. To generate a high energy intermediate for the reaction that has more favorable reactivity. Usually involves phosphorylation: transfer of phosphate group to a reactant (then becomes a phosphorylated intermediate: phosphorylation and dephosphorylation promote crucial protein shape changes.
