Ch. 6: An Introduction to Metabolism The chemistry of life…..

Metabolism Catabolic pathways Anabolic pathways e.g. cellular respirations Anabolic pathways e.g. protein synthesis

Organisms transform energy KE = Kinetic Energy, energy in motion PE = Potential Energy, energy stored energy can be transformed from one form to another

Laws of Thermodynamics The first law of thermodynamics E is neither created or destroyed The second law of thermodynamics Entropy organisms live at the expense of free energy exergonic reactions endergonic reactions

Disequilibrium Cell that reaches equilibrium is dead Open System Sequence of reactions Coupling: use of an exergonic process to drive an endergonic one

Why do I have to do all this work! ATP

ATP structure chemical reaction that results in the release of energy How does ATP perform work? Phosphorylation Transfer Regeneration of ATP

Phosphorylation of ATP

ATP …that 107 molecules of ATP are used and then regenerated per second per cell? Did you know?

Enzymes Speed up reaction rate: Catalyst Catalytic Protein Activation Energy needed

Exergonic Reaction Enzymes lower barrier of activation energy Does not speed up reaction. Hastens reactions that would occur normally.

Enzymes Active Site

Inhibition of Enzymes

The control of metabolism regulated by controlling enzyme activity allosteric regulation feedback inhibition cooperativity location of enzymes in the cell