Metabolism Energy of Life

Metabolic Pathways Anabolic Pathways Catabolic Pathways

Kinetic Energy

Potential Energy

Laws of Thermodynamics

First Law of Thermodynamics Energy can be transferred or transformed but it cannot be created or destroyed

Second Law of Thermodynamics Every energy transfer or transformation increases the entropy of the Universe

Free Energy J. Willard Gibbs Gibbs Equation Yale Professor (1839-1903) Yale Professor Mathematical physics Gibbs Equation DG = DH – TDS DG – Change in Free energy DH – Change in Total energy (Enthalpy) T – Absolute temperature in Kelvin DS – Change in Entropy

Free Energy and Metabolism

Free Energy and Metabolism Exergonic Reactions Release of energy -DG Spontaneous Downhill More energy in reactants than in products Ex. Cellular Respiration -686 kcal/mol Ex. ATP  ADP + P -7.3 kcal/mol Endergonic Reactions Absorbs energy +DG Nonspontaneous Uphill More energy in products than in reactants Ex. Photosynthesis +686 kcal/mol Ex. ADP + P  ATP +7.3 kcal/mol

Adenosine Triphosphate

Energy Coupling using ATP hydrolysis

How ATP Performs Work

The ATP Cycle

Enzymes Biological Catalyst Speed up metabolic reactions by lowering the energy of activation

Exergonic Reaction

Exergonic Reaction with Enzyme

Enzymes Substrate Specific Active Site Induced Fit Recycled

Enzymes Cofactors Coenzymes

Enzymes Inhibitors Competitive Noncompetitive

Enzymes Allosteric Sites Cooperativity

Feedback Inhibition Pathway switched off