1. WORK

2. Cell Metabolism and ATP
ATP is the energy molecule of the cell.
Billions are used and reassembled every second!!
Endergonic Rxn – Requires energy
(ie. Photosynthesis)
Exgergonic Rxn – releases energy
(ie.Cellular Respiration)
Glucose = 1 dollar
ATP = 1 penny

3. Our “Key” to Biochemical Reactions
Enzymes
Our “Key” to Biochemical Reactions

4. ENZYMES Proteins that accelerate chemical reactions
Almost all processes in the cell need enzymes in order to occur – Cellular Respiration, Photosynthesis, food digestion etc.
Are extremely selective – very specific to certain reactions

5. ENZYMES
For Example:
Lysozyme digests bacterial cell walls, and is found in human tears, egg-white, etc

6. ENZYMES
Enzymes are known to catalyze about 4,000 reactions in the human body
Named according to the reaction they catalyze … “ase” is added to the name of the substrate
Ex: Lactase breaks down lactose

7. HOW ENZYMES WORK:
By providing a lower activation energy for a reaction and dramatically accelerating its rate
For example… (Do not copy)
the reaction catalysed by orotidine-phosphate decarboxylase will consume half of its substrate in 78 million years if no enzyme is present. However, when the decarboxylase is added, the same process takes just 25 milliseconds

8. HOW ENZYMES WORK: Enzyme SUBSTRATE PRODUCT(S) Eg: Sucrase
Sucrose + Water Glucose + Fructose
Enzymes help a reaction to occur …
without being directly involved!!!

9. HOW ENZYMES WORK:
“Lock and Key” Model:

10. HOW ENZYMES WORK:

11. Competitive Inhibitors
A molecule similar in shape to the substrate bonds with the enzyme’s active site and inhibit its function.
Poisons: cyanide and arsenic bind to key enzymes in this manner…death may result!

12. F.Y.I: Carbohydrases break down ________
Proteases break down… ________
Lipases break down… ________

13. ENZYMES Work at optimal temp. & pH
If it is too hot, an enzyme can become DENATURED… and will no longer function properly

14. The End!!!