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Energy, Catalysis and Biosynthesis. Complexity of metabolism. Metabolism. *catabolism *anabolism. *potential energy. Conservation of Energy. Energy is defined as the capacity to perform work. Kinetic energy is the energy of motion. Potential energy is stored energy.
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Energy, Catalysis and Biosynthesis Complexity of metabolism Metabolism *catabolism *anabolism *potential energy
Conservation of Energy Energy is defined as the capacity to perform work. Kinetic energy is the energy of motion. Potential energy is stored energy.
Free energy, stability, and change Free energy Change in free energy = DG Gravitational Motion Diffusion Chemical Reaction
*energetically unfavorable *energetically favorable Free energy, stability, and change Equilibrium *chemical equilibrium DG = 0, no net change in the system Chemical reactions with free energy changes:
*Multistep open hydroelectric system Metabolic Disequilibrium
Enzymes • Metabolism is the total of all chemical reactions in an organism. • Most metabolic reactions require the assistance of enzymes, proteins that speed up chemical reactions.
Enzymes Induced Fit
Enzymes Enzymes lower the barrier of EA Enzymes are catalytic proteins
Activation Energy • Activation energy • Activates the reactants • Triggers a chemical reaction • Enzymes lower the activation energy for chemical reactions. Activation energy barrier Activation energy barrier reduced by enzyme Enzyme Reactant Reactant Energy level Energy level Products Products (b) With enzyme (a) Without enzyme
Enzymes Physical and chemical properties affect enzyme activity: Substrate Active site *activators *cofactor Substrate Inhibitor *coenzyme Active site *inhibitors Substrate Active site Inhibitor
ATP and Cellular Work Main types of (cellular) work: mechanical transport chemical
Energy Triphosphate Diphosphate Adenosine Adenosine P P P P P P Phosphate (transferred to another molecule) ATP ADP The Structure of ATP • ATP (adenosine triphosphate) • Consists of adenosine plus a tail of three phosphate groups • Is broken down to ADP and a phosphate group, releasing energy
ATP and Cellular Work Motor protein ATP ADP P ADP P Protein moved (a) Motor protein performing mechanical work Solute Transport protein P P ATP ADP P Solute transported (b) Transport protein performing transport work P X P X Y ATP ADP P Y Reactants Product made (c) Chemical reactants performing chemical work