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

2. ENZYMES Proteins that accelerate chemical reactions
Almost all processes in the cell need enzymes in order to occur
Are extremely selective – very specific to certain reactions

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

4. 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

5. 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 5'-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

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

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

8. HOW ENZYMES WORK:

9. ENZYMES Work at optimal temp. & pH
If it is too hot or at wrong pH, enzyme becomes DENATURED… no longer function properly

10. ENZYME LAB
Anyone for Liver?

11. The End!!!