1. Metabolism and enzymes
Mader Biology Chapter 6

2. Metabolism

3. ATP is the cell’s source of energy

4. Reactions can be endergonic or exergonic
Exergonic (exothermic)
Endergonic (endothermic)
Releases energy
ATP  ADP + P
Absorbs energy
ADP + P  ATP

5. Coupling
Living systems couple endergonic with exergonic reactions

6. Kinetic Energy vs Chemical Energy
Kinetic Energy Chemical Energy Energy of movement Energy stored in bonds

7. Enzymes

8. Enzymes Functional proteins Used to catalyze chemical reactions
They do this by decreasing the amount of activation energy needed for the reaction to occur

9. Anatomy of an Enzyme
Substrate binds at the active site

10. Enzymes Don’t get changed or used up in the reaction
Work on highly specific substrates
Substrate attaches to Active Site with of the enzyme and is converted to product

11. Competitive vs. Non-competitive Inhibition
COMPETITIVE INHIBITOR:
Takes the place of the normal substrate
Does not change the ‘shape’ of the active site
Usually reversible
NON-COMPETITIVE INHIBITOR:
Attaches to the allosteric site (different than the active site)
Changes the shape of the enzyme, and thereby the active site.
Many are non reversible.

12. Factors affecting Enzymes
Many will not work properly without Cofactors (inorganic- ex: Zn, Fe) or Coenzymes (organic). Most coenzymes are vitamins or vitamin derivatives
Denaturation: pH
Temp
Salinity