1. 1 SURVEY OF BIOCHEMISTRY Glycogen

2. 2 What is Glycogen? Branched polymer of glucose Storage form of glucose –Liver Maintenance of blood glucose levels, especially during fasting –Skeletal Muscle Fuel reserve for synthesis of ATP for muscle contraction Draw Structure

3. 3 Types of Polysaccharide Linkages What is an alpha 1->4 linkage? What is a beta 1->4 linkage? How are monosaccharides branched at C6? Illustrate

4. 4 Branched Structure of Glycogen What is meant by non-reducing vs. reducing end?

5. 5 Reducing v. Nonreducing Sugars A reducing sugar has an anomeric C that has NOT formed a glycosidic bond, such that it can reduce oxidizing agents. Recall what an anomeric C is!

6. 6 Reducing v. Nonreducing Sugars Glycogen has one reducing end. All other ends are non-reducing.

7. 7 A Closer Look at Glycogen Today: Glycogen Breakdown Monday: Glycogen Synthesis Wednesday: Control of Glycogen Synthesis

8. 8 Three Enzymes Involved in Glycogen Breakdown Glycogen Phosphorylase –Produces Glucose 1-Phosphate –Uses Pyridoxal 5’-Phosphate (cofactor) Glycogen Debranching Enzyme –2 Enzymatic functions Produces glucose Transfers branches onto main polymer chain Phosphoglucomutase

9. 9 Glycogen Phosphorylase Glycogen phosphorylase uses the cofactor pyridoxal 5’-phosphate to catalyze production of glucose 1-phosphate from a terminal end of glycogen.

10. 10 Glycogen Phosphorylase Mechanism 1.Formation of a ternary complex Glycogen + P i +

11. 11 Glycogen Phosphorylase Mechanism 2. Formation of an oxonium intermediate

12. 12 Glycogen Phosphorylase Mechanism 3. Formation of glucose 1-phosphate + Glycogen n-1 Glucose 1-Phosphate

13. 13 Three Enzymes Involved in Glycogen Breakdown Glycogen Phosphorylase –Produces Glucose 1-Phosphate –Uses Pyridoxal 5’-Phosphate (cofactor) Glycogen Debranching Enzyme –2 Enzymatic functions Produces glucose Transfers branches onto main polymer chain Phosphoglucomutase

14. 14 Glycogen Debranching Enzyme Transferase activity

15. 15 Phosphoglucomutase

16. 16 Glycogen Debranching Enzyme Transferase activity

17. 17 How To Study Learn all 10 steps of Glycolysis –Substrates –Products –Enzymes –Know general process by which mechanisms occur Learn 3 enzyme activities used to break down glycogen

18. 18 PRS What is the maximum number of O 2 molecules that hemoglobin can bind? 1.One 2.Two 3.Three 4.Four

19. 19 PRS What is the product formed by the activity of triose phosphate isomerase in glycolysis? 1.Glucose 1-phosphate 2.Glucose 6-phosphate 3.Glyceraldehyde 3-phosphate 4.Pyruvate

20. 20 PRS How many ATP’s are produced after the first stage (Steps 1-5) of glycolysis? 1.None 2.One 3.Two 4.Four

21. 21 PRS Which of the following vitamins are fat soluble? 1.Vitamin C 2.Vitamin A 3.Riboflavin 4.Folate

22. 22 PRS B cells mature in the ________. 1.Thymus 2.Bone marrow 3.Muscle tissue 4.Myosin

23. 23 PRS Oxygen binding to myoglobin results in what shaped curve? 1.Sigmoidal 2.Hyperbolic 3.Linear 4.Sinusoidal

24. 24 PRS Which of the following amino acids is not in the catalytic triad of serine proteases? 1.Ser 2.Thr 3.His 4.Asp

25. 25 PRS What is K m ? 1.The catalytic efficiency 2.The catalytic rate constant 3.1/2 V max 4.[S] at 1/2 V max