Biochemistry: Metabolism

Document Content and Description Below

Biochemistry: Metabolism What are the four metabolic reactions that happen only inside the mitochondria? - ✔✔1. Fatty acid oxidation 2. Acetyl-CoA production 3. TCA cycle 4. Oxidative phospho ... rylation What are the five metabolic reactions that happen only in the cytoplasm? - ✔✔1. Glycolysis 2. Fatty acid synthesis 3. HMP shunt 4. Protein synthesis (RER) 5. Steroid synthesis (SER) What are the three metabolic reactions that happen in both the cytoplasm and the mitochondria? - ✔✔1. Heme synthesis 2. Urea cycle 3. Gluconeogenesis ***HUGs take two*** What is the common definition of a kinase? - ✔✔Uses ATP to add high energy phosphate group onto substrate What is the common definition of a phosphorylase? - ✔✔Adds inorganic phosphate onto substrate without using ATP What is the common definition of a phosphatase? - ✔✔Removes phosphate group from substrate What is the common definition of a dehydrogenase? - ✔✔Oxidizes substrate What is the common definition of a carboxylase? - ✔✔Adds 1 carbon with the help of biotin What is the rate determining enzyme of glycolysis? - ✔✔Phosphofructokinase-1 (PFK1) What is the rate determining enzyme of gluconeogenesis? - ✔✔Fructose-1,6- bisphosphatase What is the rate determining enzyme of TCA cycle? - ✔✔Isocitrate dehydrogenase What is the rate determining enzyme of glycogen synthesis? - ✔✔Glycogen synthase What is the rate determining enzyme of glycogenolysis? - ✔✔Glycogen phosphorylase What is the rate determining enzyme of the HMP shunt? - ✔✔Glucose-6-phosphate dehydrogenase What is the rate determining enzyme of de novo pyrimidine synthesis? - ✔✔Carbamoyl phosphate synthetase II What is the rate determining enzyme of de novo puring synthesis? - ✔✔GlutaminePRPP amidotransferase What is the rate determining enzyme of the urea cycle? - ✔✔Carbamoyl phosphate synthetase I What is the rate determining enzyme of fatty acid synthesis? - ✔✔Acetyl-CoA carboxylase (ACC) What is the rate determining enzyme of fatty acid oxidation? - ✔✔Carnitine acyltransferase I What is the rate determining enzyme of ketogenesis? - ✔✔HMG-CoA synthase What is the rate determining enzyme of cholesterol synthesis? - ✔✔HMG-CoA reductase How many ATP does the aerobic metabolism of glucose produce in the heart, liver, and muscle? - ✔✔1. Heart and liver: 32 via malate aspartate shuttle 2. Muscle: 30 via glycerol-3-phosphate shuttle How many ATP is produced by anaerobic glycolysis? - ✔✔2 ATP per glucose What can be coupled to unfavorable reactions to make them proceed? - ✔✔ATP hydrolysis What are the seven activated carriers? - ✔✔1. ATP (phosphoryl) 2. NADH, NADPH, FADH2 (electrons) 3. Coenzyme A, lipoamide (acyl) 4. Biotin (CO2) 5. Tetrahydrofolates (1-carbon units) 6. SAM (1-carbon units) 7. Thiamine pyrophosphate (aldehydes) What are the three universal electron acceptors? - ✔✔1. NAD+ 2. NADP+ 3. FAD+ What are NAD+ and NADP+ called? - ✔✔Nicotinamides What is FAD+ called? - ✔✔Flavin nucleotides Where is NADPH primarily produced? - ✔✔HMP shunt What type of processes NAD+ generally used for? - ✔✔Catabolic processes to carry reducing equivalents away as NADH What type of processes is NADPH generally used for? - ✔✔Anabolic processes (steroid and fatty acid synthesis) as a supply of reducing equivalents What are the four specific places NADPH is used? - ✔✔1. Anabolic processes 2. Respiratory burst 3. P-450 4. Glutathione reductase What is the purpose of hexokinase and glucokinase? - ✔✔To catalyze the phosphorylation of glucose-6-phosphate What is the first step of glycolysis and glycogen synthesis? - ✔✔Phosphorylation of glucose to yield glucose-6-phosphate Which enzyme catalyzes the first step of glycolysis in the liver and beta-cells of the pancrease? - ✔✔Glucokinase What are four properties of glucokinase? - ✔✔1. High Vmax 2. High kM 3. Induced by insulin 4. No feedback inhibition by glucose-6-phosphate ***GLUcokinase is a GLUtton; it has a high Vmax because it cannot be satisfied*** Which enzyme catalyzes the first step of glycolysis in most cells of the body? - ✔✔Hexokinase What are four properties of hexokinase? - ✔✔1. Low Vmax 2. Low kM 3. Uninduced by insulin 4. Feedback inhibited by glucose-6-phosphate What is the purpose of glucokinase? - ✔✔To phosphorylate excess glucose after a meal to sequester it in the liver, allowing the liver to serve as a blood glucose "buffer" What is the net reaction of glycolysis in the cytoplasm? - ✔✔Glucose + 2Pi + 2ADP + 2NAD+ -> 2 Pyruvate + 2ATP + 2NADH + 2H+ + 2H2O Which two reactions in glycolysis require the addition of ATP? - ✔✔1. Glucose -> Glucose-6-phosphate (hexokinase) 2. Fructose-6-phosphate -> fructose-1,6-bisphosphate (phosphofructokinase-1) What molecule provides feedback to the hexokinase reaction, and which kind of feedback is it? - ✔✔Glucose-6-phosphate (negative) Which two molecules provide positive feedback to the PFK1 reaction? - ✔✔1. AMP 2. Fructose-2,6,-bisphosphate Which two molecules provide negative feedback to the PFK1 reaction? - ✔✔1. ATP 2. Citrate Which two reactions of gycolysis produce ATP? - ✔✔1. 1,3-Bisphosphoglycerate -> 3- phosphoglycerate (phosphoglycerate kinase) 2. Phosphoenolpyruvate -> pyruvate (pyruvate kinase) Which two molecules provide negative feedback to the pyruvate kinase reaction? - ✔✔1. ATP 2. Alanine Which molecule provides positive feedback to the pyruvate kinase reaction? - ✔✔Fructose-1,6-bisphosphate Which reaction in glycolysis produces acetyl-CoA? - ✔✔Pyruvate -> Acetyl CoA (pyruvate dehydrogenase) Which three molecules provide negative feedback on the pyruvate dehydrogenase reaction? - ✔✔1. ATP 2. NADH 3. Acetyl-CoA What is the major allosteric regulator of the PFK1 reaction? - ✔✔Fructose-2,6- bisphosphate How is the PFK1 reaction regulated during fasting? - ✔✔1. Glucagon is increased, causing: 2. An increase in cAMP, causing: 3. Increased protein kinase A, causing: 4. Increased fructose-1,6-bisphosphatase and decreased phosphofructokinase-2, leading to: 5. Gluconeogenesis How is the PFK1 reaction regulated during the fed state? - ✔✔1. Insulin is increased, causing: 2. Decreased cAMP, causing: 3. Decreased cAMP, causing: 4. Decreased fructose-1,6-bisphosphatase and increased phosphofructokinase-2 5. Glycolysis Which reaction is catalyzed by the pyruvate dehydrogenase complex? - ✔✔Pyruvate + NAD+ + CoA -> Acetyl-CoA + CO2 + NADH What are the five cofactors in the pyruvate dehydrogenase complex? - ✔✔1. Pyrophosphate (B1, thiamine; TPP) 2. FAD (B2, riboflavin) 3. NAD (B3, niacin) 4. CoA (B5, pantothenate) 5. Lipoic acid What complex is the pyruvate dehydrogenase complex similar to, and where is this other complex found?? - ✔✔Alpha-ketoglutarate dehydrogenase complex of the TCA cycle What does arsenic inhibit? - ✔✔Lipoic acid What are the findings of arsenic poisoning? - ✔✔1. Vomiting 2. Rice water stools 3. Garlic breath How does exercise affect the NAD+/NADH ratio, ADP, and calcium? - ✔✔1. NAD+/NADH ratio increased 2. ADP increased 3. Calcium increased What two substrates increase in the presence of pyruvate dehydrogenase deficiency? - ✔✔1. Pyruvate 2. Analine What is the metabolic result of pyruvate dehydrogenase deficiency? - ✔✔Lactic acidosis What are two potential causes of pyruvate dehydrogenase activity? - ✔✔1. Congenital 2. Acquired, usually in alcoholics due to vitamin B1 deficiency What findings are seen in pyruvate dehydrogenase deficiency? - ✔✔Neurologic deficits What is the treatment for pyruvate dehydrogenase deficiency? - ✔✔Increased intake of ketogenic nutrients to avoid the glycolytic pathway (e.g., high fat content or high lysine and leucine) What are the two purely ketogenic amino acids? - ✔✔1. Lysine 2. Leucine What are the four fates of pyruvate? - ✔✔1. Alanine (by ALT) 2. Lactate (by lactose dehydrogenase) 3. Oxaloacetate (by pyruvate carboxylase) 4. Acetyl-CoA (by pyruvate dehydrogenase) What is the purpose of the lactic acid pathway of anaerobic glycolysis? - ✔✔To regenerate NAD+ In which six tissues is anaerobic glycolysis the major pathway of energy production? - ✔✔1. RBCs 2. Leukocytes 3. Kidney medulla 4. Lens 5. Testes 6. Cornea What is the function of the pyruva [Show More]

Last updated: 3 years ago

Preview 1 out of 30 pages