1. Biochemistry Part V - (Enzymes)

2. Enzymes are extremely important proteins!
They are the catalysts, which support homeostasis within our cells, by keeping safe and practical for living tissue.
Every second of every minute, each of us is a living, breathing biological machine!
100 trillion cells play the symphony called metabolism in perfect pitch, and the musicians are enzymes!

3. These important proteins (enzymes):
Make reactions happen faster or easier, by lowering the activation energy required for a reaction.
Are very specific; one enzyme for one reaction!
Can be used over and over again

4. Enzymes (cont’d)
Enzymes have “active sites” where the substance they catalyze can attach. That substance is called the substrate.
Their shapes match perfectly, like a lock and key.
After the reaction, the substrate is released and the enzyme does it’s job over again.

5. Enzymes (cont’d)
Example: catalase (a.k.a. peroxidase) is an enzyme that breaks down H2O2 into H2O and O2. Catalase has an active site that perfectly matched H2O2 (the substrate!).

6. Enzymes (cont’d)
Enzymes operate within an optimum temperature and pH range. Otherwise, they denature (change their shape), which means the substrate they catalyze no longer matches their active site.

8. Examples of why enzymes are so important:
1. PKU (Phenylketonuria) – a disorder resulting from a missing enzyme, which metabolizes the amino acid phenylalanine. This amino acid is used in the body to produce skin pigment, important brain chemicals, hormones, etc. It is also used in nutria-sweet.

9. Enzymes – PKU (cont’d)
Without the enzyme, this will build up as a brain poison, leading to severe mental delays by age 2!

10. Enzymes – PKU (cont’d)
The solution? All babies not have PKU tests at birth and if they are determined to have the disorder, they are put on a special diet (lacking phenylalanine) until ages 6-10, when doctors say the disorder no longer exists. Special situation – a pregnant woman must go back on the diet when she is pregnant!

11. Enzyme importance (cont’d)
2. Lesch-Nyhan Syndrome – 1 missing enzyme leads to self mutilation, a tragic behavioral consequence.

12. Enzyme importance (cont’d)
3. Shortage of enzyme lactase? You will probably have some degree of lactose intolerance, (predominant sugar in milk)! Results are very distressing – nausea, gas, diarrhea, etc.