10. Please compare the events of cell apoptosis and necrosis. (10%)

6. Please briefly descript the mechanisms of DNA repair. (10%)

7. What is co-translational translocation? What is post-translational translocation? Please compare their benefits or defects in protein translocation. (10%)

8.Three classes of cell-surface receptors above ion-channel-coupled receptor, G-protein-coup and enzyme-coupled receptors. Please give an example of each one to explain their characterizations and down stream molecular events. (10%)

9.Please describe what the molecular events happened in each cell cycle phase and how control-system regulate cell cycle progress. (10%)

1. If an enzyme-catalyzed reaction has a velocity of 2 mM/min and a Vmax of 10 mM/min when the substrate concentration is 0.5 mM, what is the KM? (10%)

2. Given the following plot of oxygen binding versus pressure of O2 for myoglobin and hemoglobin at pH 7.2, (1) draw a curve that shows what happens when the pH is increased to about 7.6 and (2) draw a curve that shows what happens when the pH is decreased to about 6.8. (3) What is the pH value at which hemoglobin has higher affinity of O2? Please provide the explanation from the curves. (10%)

3. β-oxidation: (1) Please plot the 4 steps of β -oxidation reaction and label the enzyme and the involved energy molecules of each step (10%). (2) Please determine the number of ATP equivalents if we complete β -oxidation of a palmitic acid (C18:0) to CO2 and H2O. By the calculation, how many kJ can be generated by 1g palmitic acid if the molecular weight of B-linolenic acid is 256 Da? (Assume for the calculation that NADPH is worth 3.5 ATPs, NADH is 2.5 ATPs, FADH2 is 1.5 ATPs and one Acetyl- CoA produces 10 ATPs and the bydrolytic energy of ATP is 31 kJ/mol) (10%).

4.How many NADH, FADH2 and GTP can be generated for one molecule of acetyl-CoA passing through TCA cycle? How many ATP can be produced if these NADH, FADH2 and GTP passing through electric transfer system? (10%)

5. What is the start building block of cholesterol? What is the control enzyme for cholesterol biosynthesis? What is the major transporter of cholesterol in circulation system? How the cells manipulate the oversupply of cholesterol? (10%)

1.(15%) Find the local maximum and minimum values and saddle  points  of the function f(x,y)=ey(y2-x2).