1. Proteins Bell work Get out journal and turn to pH lab for me to check.1

2. Essential to all life.
Composed of amino acids (monomer)
There are 20 different amino acids found in living organisms.

3. Composed of… Carbon, hydrogen, oxygen, and nitrogen (CHON)
Amino acids are held together by a peptide bond.

4. enzymes and antibodies
Found in…
Muscle/meat
skin
hair
enzymes and antibodies

5. Functions Give structure (bone and muscle)
Transport nutrients in and out of cell
Allow muscles to contract (chemical messengers)
Speed up chemical reactions

6. Test = Biurets
Positive violet
Pink means peptides present

7. Enzymes

8. What Are Enzymes? Most enzymes are Proteins
Act as Catalyst to accelerate a reaction
Not permanently changed in the process

9. Enzymes Are specific for the reaction they will catalyze Are Reusable
End in –ase
-Sucrase
-Lactase
-Maltase

10. How do enzymes Work?
Enzymes work by weakening bonds which lowers activation energy

11. Enzymes Without Enzyme With Enzyme Free Energy
Progress of the reaction
Reactants
Products
Free energy of activation

13. Enzyme-Substrate Complex
The substance (reactant) an enzyme acts on is the substrate
Enzyme-substrate complex = when the substrate joins the enzyme
Enzyme
Joins
Substrate

14. Active Site
A restricted region of an enzyme molecule which binds to the substrate.
Active Site
Enzyme
Substrate

15. What Affects Enzyme Activity?

16. 1. Environmental Conditions
1. Extreme Temperature are the most dangerous
- high temps may denature (unfold) the enzyme.
2. pH (most like pH near neutral)
3. Ionic concentration (salt ions)

17. 2. Cofactors and Coenzymes
Inorganic substances (zinc, iron) and vitamins (respectively) are sometimes need for proper enzymatic activity.
Example:
Iron must be present in the quaternary structure - hemoglobin in order for it to pick up oxygen.

18. 3. Two examples of Enzyme Inhibitors
a. Competitive inhibitors: are chemicals that resemble an enzyme’s normal substrate and compete with it for the active site.
Enzyme
Substrate
Competitive inhibitor

19. Inhibitors b. Noncompetitive inhibitors:
Inhibitors that do not enter the active site, but bind to another part of the enzyme causing the enzyme to change its shape, which in turn alters the active site.
Enzyme
Noncompetitive
Inhibitor
Substrate
active site
altered