Into which two very important substances can HMG-CoA be converted?
1. HMG-CoA is converted to mevalonate by HMG-CoA reductase, HMGR. This conversion is a crucial step in the biosynthesis of cholestrol.
2. Acetoacetate is formed in mitochendria from HMG-CoA by HMG-CoA lyase.
In the reaction below HMG-CoA it is converted to mevalonate. What is the structure of mevalonate (A-D). NADP O HOCH SCOA hydroxymethylglutaryl-CoA (HMG-CoA) mevalonate Possible structures (A-D) x x Il be OA
Statin drugs, like Mevacor (lovastatin) and Lipitor (atorvastatin), act as competitive inhibitors of HMG-CoA reductase by mimicking the structure of mevalonate. However, it is not this inhibition that directly lowers cholesterol levels in the blood. What enzymatic reaction does HMG CoA-reductase catalyze? What is important about this step of cholesterol synthesis? How can statins mechanistically cause a decrease in LDL cholesterol in the blood if it is not a direct effect of decreased cellular cholesterol synthesis?
Which of the following can be converted to acetyl-CoA? glucose only glucose and fatty acids Oglucose, fatty acids, and ketogenic amino acids fatty acids only
SERBP, SCAP, Insig and Sec are proteins associated with regulating the synthesis of HMG-CoA reductase and other enzymes of cholesterol synthesis and uptake. What compounds bind to SCAP and Insig to down-regulate HMG- CoA reductase and cholesterol synthesis? A. ammonia and urea, B. glutamate and glutamine, OC. sterols and oxysterols, OD IMP and OMP, O E. all of the above, OF none of the above, QUESTION 15 The synthesis of which of the following compounds requires the most ATP and...
8. Which medication inhibits the action of the HMG-CoA reductase enzyme and lower LDL cholesterol levels? a. Atorvastatin b. Cholestyramine c. Niacin d. Fenofibrate 9. Which medication is a direct vasodilating drug is so toxic that its use is limited to 3 days? a. Hydralazine b. Isosorbide dinitrate c. Nitroglycerin d. Sodium nitroprusside 10. Which of the following information is accurate regarding drugs used to regulate heart rate? (Select all that apply.) a. These drugs work by blocking actions of...
Threonine is converted to succinyl CoA through a process that produces 1 molecule of ammonia and 1 NADH while requiring 1 ATP. Consider that the resulting succinyl CoA can use a portion of the citric acid cycle to be converted to oxaloacetate. 1. (2 points) How many molecules of threonine would be required to produce one molecule of glucose? 2. (6 points) What is the net consumption or production of NADH, FADH2, and ATP for the synthesis of one molecule...
Question 3 Glucose labeled with 14C in C-3 and C-4 is completely converted to acetyl-CoA via glycolysis and the pyruvate dehydrogenase complex. What percentage of the acetyl-CoA molecules formed will be labeled with 14C, and in which position of the acetyl moiety will the 14C label be found? Select the correct answer and explain your reasoning 100% of the acetyl-CoA will be labeled at C-1 (carboxyl). 100% of the acetyl-CoA will be labeled at C-2. 50% of the acetyl-CoA will...
Question 3 Glucose labeled with 14C in C-3 and C-4 is completely converted to acetyl-CoA via glycolysis and the pyruvate dehydrogenase complex. What percentage of the acetyl-CoA molecules formed will be labeled with 14C, and in which position of the acetyl moiety will the 14C label be found? Select the correct answer and explain your reasoning 100% of the acetyl-CoA will be labeled at C-1 (carboxyl). 100% of the acetyl-CoA will be labeled at C-2. 50% of the acetyl-CoA will...
Question 3 Glucose labeled with 14C in C-3 and C-4 is completely converted to acetyl-CoA via glycolysis and the pyruvate dehydrogenase complex. What percentage of the acetyl-CoA molecules formed will be labeled with 14C, and in which position of the acetyl moiety will the 14C label be found? Select the correct answer and explain your reasoning 100% of the acetyl-CoA will be labeled at C-1 (carboxyl). 100% of the acetyl-CoA will be labeled at C-2. 50% of the acetyl-CoA will...
Question 3 Glucose labeled with 14C in C-3 and C-4 is completely converted to acetyl-CoA via glycolysis and the pyruvate dehydrogenase complex. What percentage of the acetyl-CoA molecules formed will be labeled with 14C, and in which position of the acetyl moiety will the 14C label be found? Select the correct answer and explain your reasoning 100% of the acetyl-CoA will be labeled at C-1 (carboxyl). 100% of the acetyl-CoA will be labeled at C-2. 50% of the acetyl-CoA will...