Biology 638 Biochemistry II Exam-3. (Note that you are not allowed to use any calculator)

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1 Biology 638 Biochemistry II Exam-3 (Note that you are not allowed to use any calculator) 1. In the non-cyclic pathway, electron pathway is. Select the most accurate one. a. PSII PC Cyt b 6 f PC PSI Fd-NADP + reductase Fd NADPH b. PSII PQ Cyt b 6 f PC PSI Fd Fd-NADP + reductase NADPH c. PSII PC Cyt b 6 f PQ PSI Fd-NADP + reductase Fd NADPH d. PSII PQ Cyt b 6 f PQ PSI Fd Fd-NADP + reductase NADPH The following sequence of reactions represents the β-oxidation pathway for fatty acids in mitochondria. Fatty acid E 0 Acetyl-CoA E 4 F 1 E 1 F 4 F 2 E 3 E 2 F 3 F 1, F 2, F 3, and F 4 are substrates. E 0, E 1, E 2, E 3, and E 4 are enzymes. The following two questions refer to this pathway. 2. F 4 is. a. β-ketoacyl-coa b. trans-δ 2 -enoyl-coa c. β-hydroxyacyl-coa d. fatty acyl-coa 3. E 3 is a(n). a. hydratase b. hydrolase c. isomerase d. thiolase e. None of them

2 4. How many acetyl-coa and ATP molecules are required to make ten glucose molecules through the glyoxylate pathway and gluconeogenesis? Assume that NADH, FADH 2, and GTP are equivalent to three, two and one ATP, respectively. a. 40 Acetyl-CoA and 40ATP b. 20 Acetyl-CoA and 40 ATP c. 40 Acetyl-CoA and 20 ATP d. 20 Acetyl-CoA and 20 ATP e. None of them 5. How many moles of ATP are produced from the complete oxidation of (cis Δ 9,12,15 C 21 ) fatty acid to CO 2? a. 164 b. 166 c. 168 d. 170 e. None of them 6. Select the correct pathway of Cori cycle. a. In muscle (glucose lactate pyruvate) via blood to liver (pyruvate lactate glucose) via blood to muscle (glucose so on). b. In liver (glucose pyruvate lactate) via blood to muscle (lactate pyruvate glucose) via blood to liver (glucose so on). c. In liver (glucose lactate pyruvate) via blood to muscle (pyruvate lactate glucose) via blood to liver (glucose so on). d. In muscle (glucose pyruvate lactate) via blood to liver (lactate pyruvate glucose) via blood to muscle (glucose so on).

3 7. Assume that you are a CSI agent and examine a liver specimen from a fresh body. You find that the [NADP + ]/[NADPH] ratio is 0.1, and the liver specimen smell sweet. Your suggestion of cause of death is:. a. natural death by poor nutrition b. CN - poisoning c. suffocation d. large dose of epinephrine injection e. large dose of KCl injection (Very high K + ion in blood stops heart beat) 8. When O 2 instead of CO 2 enters in Calvin cycle, is produced instead of GAP. a. CO 2 b. 3PG c. 2PG d. R5P e. None of them 9. The overall β-oxidation of C 16 fatty acid is: C 16 -fatty acid + [X]FAD + [Y]NAD + + [Z]CoA + [W]ATP [a]acetyl-coa + [b]fadh 2 + [c]nadh + [W](ADP + P i ) W is. a. 2 b. 4 c. 8 d. 10 e. None of them 10. How many ATP molecules are produced from complete oxidation of two glucose molecule in the pentose phosphate pathway? Assume that one NADPH is equivalent to 3 ATPs. a. 66 b. 68 c. 70 d. 72 e. Non of them 11. Assume that a CAM plant produces ten G6P using a best combination of the cyclic and noncyclic pathways (i.e., you cannot assume that NADPH is equivalent to three ATP). How many photons are necessary for this synthesis? Select the closet one. a. 500 b. 550 c. 600 d. 650 e. 700

4 For question 12 25, select that statement that contains the most significant mistake(s). If none of (a, b, c, d) does not contain significant mistake(s) (i.e. all statements are correct), then select. 12. The followings are some descriptions of pyruvate carboxylase. a. Pyruvate carboxylase has a covalently connected biotin in the active site. b. Pyruvate carboxylase is inhibited by alanine. c. Acetyl-CoA is a powerful allosteric activator of pyruvate carboxylase. - d. In the pyruvate carboxylase reaction, HCO 3 is phosphorylated by ATP and the phosphorylated HCO - 3 reacts with the bound cofactor. 13. The followings are some descriptions of carbohydrate metabolism. a. If isocitrate lyase and malate synthase are present in mitochondrion of animal liver cells, animal can synthesize glucose from either amino acids or fatty acids. b. If liver PFK-2/FBPase-2 is replaced with the heart muscle isozyme, glucogeogenesis would not be occurred. c. If gluconeogenesis is started at pyruvate, the next compound is oxaloacetate. d. Fuctose-1,6-bisphosphatase and Glucose-6-phosphatase are only present in liver cells The followings are some descriptions of carbohydrate metabolism. a. Oligosaccharides are constructed on dolichol in the lumen of rough ER. b. The oligosaccharides on Asn are attached during the protein synthesis. c. In a posttranslational modification in Golgi apparatus, oligosaccharides are constructed on Ser or Thr residues of proteins. d. There are three distinct linkages between protein and origosaccharides. 15. The followings are some descriptions of carbohydrate metabolism. a. Transketolase has a TPP coenzyme and carries a C 2 -unit. b. Transaldolase has a neutral Lys and carries a C 3 -unit. c. Pentose phosphate pathway is controlled by the rate of the 6-phosphogluconate dehydrogenease reaction. d. Ru5P to R5P conversion in pentose phosphate pathway is catalyzed by an isomerase The followings are some descriptions of photosynthesis. a. Light reaction and dark reaction of plant photosynthesis occur in thylakoid and stroma, respectively. b. Chlorophylls cannot absorb most light between 480 nm and 620 nm wavelengths. c. Chlorophyll contains Mg 2+ ion. d. Photosynthesis is carried out at chloroplasts in plant cells.

5 17. The followings are some descriptions of photosynthesis. a. One of the most important enzymes of Calvin cycle is Rubisco. b. Rubisco is a carboxylase, but does not contain cofactor biotin. c. FBPase and SBPase are activated by Fd-NADP + reductase. d. Dark reaction in photosynthesis is called Calvin cycle. 18. The followings are some descriptions of photosynthesis and gluconeogenesis. a. Pyruvate to PEP conversion is carried out by two enzymes in gluconeogenesis. b. Pyruvate to PEP conversion is carried out by one enzyme in C 4 plants. c. Pyruvate to oxaloacetate conversion is carried out by one enzyme in gluconeogenesis. d. Pyruvate to oxaloacetate conversion is carried out two enzymes in C 4 plants The followings are some descriptions of lipid metabolism. a. Role of Ca 2+ in the active site of phospholipase A 2 is to polarize the bound water that attacks on carbonyl carbon of fatty acid. b. The acyl group of acyl-coa in cytosol is carried by carnitine into the mitochondrial matrix. c. Formation of acyl-coa requires two ATP hydrolyses (i.e., ATP + H 2 O ADP + P i is one ATP hydrolysis). d. Vitamin B 12 is required to convert methylmalonyl-coa to succinyl-coa The followings are some descriptions of lipid metabolism. a. Attaching CoA to fatty acid weakens the C α -C β bond of fatty acid. b. Very long chain fatty acids are shortened by peroxisomal β-oxidation. c. Triacylglycerol lipase is regulated by substrate availability. d. HMG-CoA lyase is a mitochondrion enzyme. 21. The followings are some descriptions of gluconeogenesis. a. Gluconeogenesis only occurs when the blood glucose level is low. b. Oxaloacetate in mitochondrion is transported by malate-aspartate shuttle whereas PEP is transported through the specific transport protein. c. In gluconeogenesis, the phosphate groups of FBP and G6P are removed by hydrolysis. d. High citrate level in liver inhibits gluconeogenesis. 22. The followings are some descriptions of pentose phosphate pathway. a. Many biological redox reactions cannot use both NADH and NADPH. b. NADPH and R5P are the major products of pentose phosphate pathway. c. About 3 % of glucose in liver is oxidized to produce NADPH. d. In many cases, GSH but not NADPH is used to reduce directly H 2 O 2 and R-O-O-H produced in cell.

6 23. The followings are some descriptions of photosynthesis. a. OEC contains a Mn 4 cluster. b. When electron flows in the non-cyclic pathway in chloroplasts, ATP and NADPH are produced. c. PQH 2 stimulates phosphorylation of LHC. d. When electron passes through Cyt b 6 f, proton is pumped from thylakoid to stroma The followings are some descriptions of rubisco. a. Rubisco activity is regulated by H + concentration in stroma. b. Rubisco activity is regulated by Mg 2+ concentration in stroma. c. Rubisco activity is regulated by CA1P concentration in stroma. d. Rubisco activity is regulated by Cl - concentration in stroma. 25. The followings are some descriptions of lipid metabolism. a. Ketone bodies are composed of acetoacetate and hydroxybutyrate, which are the major energy source during starvation. b. One acetoacetate molecule is synthesized from three acetyl-coa molecules. c. When ketone bodies are major energy source, people smell sweet. d. Ketone bodies are produced when the oxaloacetate concentration in liver is very low..