1. Energy, Catalysis and Biosynthesis
Complexity of metabolism
Metabolism
*catabolism
*anabolism
*potential energy

2. Conservation of Energy
Energy is defined as the capacity to perform work.
Kinetic energy is the energy of motion.
Potential energy is stored energy. 2

3. Free energy, stability, and change
Change in free energy = DG
Gravitational Motion
Diffusion
Chemical Reaction

4. Free energy, stability, and change
Equilibrium
*chemical equilibrium
DG = 0, no net change in the system
Chemical reactions with free energy changes:
*energetically favorable
*energetically unfavorable

5. Metabolic Disequilibrium
*Multistep open hydroelectric system

6. 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.

7. Enzymes
Induced Fit

8. Enzymes
Enzymes are catalytic proteins
Enzymes lower the barrier of EA

9. 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
(a) Without enzyme
(b) With enzyme

10. Enzymes

11. Enzymes Physical and chemical properties affect enzyme activity:
Substrate
Active site
*activators
*cofactor
Substrate
Inhibitor
*coenzyme
Active site
*inhibitors
Substrate
Active site
Inhibitor

12. ATP and Cellular Work Main types of (cellular) work: mechanical
transport
chemical 12

13. 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
Triphosphate
Diphosphate
Adenosine
Energy
ATP
ADP P
Phosphate
(transferred to
another molecule) 13

14. The Structure of ATP

15. ATP and Cellular Work Motor protein ATP ADP P ADP P Protein moved
(a) Motor protein performing mechanical work
Transport
protein
Solute P P
ATP
ADP P
Solute transported
(b) Transport protein performing transport work P
ATP X P X Y
ADP P Y
Reactants
Product made
(c) Chemical reactants performing chemical work 15

16. ATP and Cellular Work