1. Metabolism
The totality of an organism’s chemical processes, involving thousands of precisely coordinated, complex, efficient and integrated chemical reactions in the cell.

2. It’s all in the cell

3. Teaching about cell structure and function
Some different approaches
Chunking the information
Cells Alive! site

4. Enzymes = “biological catalysts”
Catalyst = chem agent that accelerates a reaction without being permanently changed
Protein
Specific
Reusable

5. Activation Energy
For reaction to occur, reactants must absorb energy to break bonds
Activation Energy is the amount of energy reactant molecules must absorb to start a chemical reaction.

6. Enzymes Lower Activation Energy
Stress bonds for catabolism (breakdown)
Orient molecules for anabolism (building)
Provide microenv. that facilitates the reaction

7. Catalytic Cycle of Enzymes

8. Factors Affecting Enzyme Activity
Temperature—increase temp, increase reaction rate, until heat denatures protein
pH – most optimal from 6-8
Ionic conc. – most enz cannot tolerate high salinity
Many adaptations are exceptions to above

9. Enzyme Inhibitors
Some chemicals selectively prevent or reduce enzyme activity
They resemble an enzyme’s normal substrate and compete for the active site
Example: function of DDT & some Ab’s