2. Protein Structure  Primary Structure – The order of amino acids.  Secondary Structure – The coiling or folding of the primary structure. This is facilitated by the carbonyl groups forming hydrogen bonds with the N-H groups.  Tertiary Structure – The folding of the coil or sheet. The form of the folding is determined by the side chains on the amino acids. Thus the order, or primary structure comes into effect here.  Quaternary Structure – Not always present, this is a complex formed by multiple tertiary forms. This is often formed around metal ions.

3. Summary of Structures

4. Secondary Structure – Alpha helix

5. Secondary Structure – Alpha Helix

6. Secondary Structure - Sheet  Sheets are formed by primary chains attached by the same H-bonds as in the helix

7. Tertiary Structure  Various interactions contribute to the formation of the structure of a protein.  Di-sulfide bonds  Salt-ion interactions, called salt bridges  Hydrogen Bonding  Hydrophobic groups interacting.

8. Tertiary Structure

9. Quaternary Structure

10. Antibodies

11. Denaturing  To “denature” a protein is to break up it’s structure. Largely, it is the tertiary structure that is disrupted, however, any disruption of secondary, tertiary or quaternary structure applies.  Denaturing may be accomplished by:  Heat  Acid or base  Heavy Metals  Agitation  Organic compounds that interact with side chains

12. Enzymes  Working proteins are functional in a myriad of ways. Some proteins act as structural elements such as that in hair or collagen. Others function as enzymes. These depend very heavily on shape as the operate via a lock and key mechanism.  This mechanism can be disrupted by similar molecules that fit within the proteins. These are called inhibitors.  Computer Animation of ATP Hydrolysis Computer Animation of ATP Hydrolysis

13. Enzymes and Inhibition

14. Advanced Glycosidic Products, (AGE’s)  Advanced Glycosidic End Products, (AGE’s), also known as Maillard Reaction Products are known to effect all tissue proteins and DNA.  Originally recognized in diabetics, then in normal individuals, AGE’s play a major role in diabetic complications including blindness, arteriosclerosis, joint stiffness, kidney disease and are correlated with chronic high blood sugar, a precursor to adult onset diabetes.  AGE’s are a principle components in what are thought to be normal aging processes. Characteristics associated with aging, both internal and external, are affected by blood sugar levels.** Krajcovivova-Kudlackova M. Physiol. Res. 51 313 (2002) and Baynes J.W. et. al. “The Mailard Reaction in Aging, Diabetes and Nutrition” publ. Alan R. Liss, N.Y.

15. Formation of cross-linked proteins Cerami A. et. al. “Glucose and Aging” Sci. Amer. 256 90 (1986)