109年 - [非官方正解]109 國立清華大學碩士班考試入學試題_生命科學院甲組：生物化學#118646

科目：研究所、轉學考(插大)◆生物化學 | 年份：109年 | 選擇題數：20 | 申論題數：5

試卷資訊

所屬科目：研究所、轉學考(插大)◆生物化學

選擇題 (20)

1. In transmembrane proteins, which amino acid is preferred at the membrane-water interface? (A)W, (B) E, (C) K, (D) L, (E) A.
2. Which transport system does not require energy input to transport substrates? (A)Ca+2-ATPase, (B) bacteriorhodopsin (C) ABC transporters, (D)potassium channel, (E) sodium pump.
3. Which of the following statement about the asymmetric structures of biological membranes is FALSE? (A) Membrane proteins display transverse and lateral asymmetry, (B) The lipids of the membrane exhibit lateral heterogeneity and transverse asymmetry, (C) The lipid composition is different from organelles to organelles, (D) The asymmetric membrane structures are maintained by transporters, (E) Acidic phospholipids are enriched in the outer leaflet.
4. Which amino acids are negatively-charged at neutral pH? (A)A, C, (B) D, E, (C) L, I, (D) K, R, (E) N, Q.
5. The rate-limiting step in glycogen catabolism is catalyzed by glycogen phosphorylase, which is activated by_______? (A) ATP, (B) ADP, (C) glucose-6-phosphate, (D) phosphorylation, (E) acetylation.
6. The biosynthesis of_______ intermediates? (A) Pro, (B) Tyr, (C) His, (D) Phe, (E) Lys. is connected to purine biosynthesis by common
7. HMG-CoA reductase is the key regulatory site in cholesterol synthesis. Which of the following statement about the regulatory mechanisms of HMG-CoA reductase is TRUE? (A) Phosphorylation by cAMP-dependent kinase activates HMG-CoA reductase, (B) A high AMP:ATP ratio leads to activation of HMG-CoA reductase, (C) High cholesterol level increases the half-life of HMG-CoA reductase, (D) High cholesterol level increases HMG-CoA reductase gene expression, (E) HMG-CoA reductase phosphatase can activate HMG-CoA reductase.
8. What is the net ATP yield from the complete oxidation of one myristate to CO2 and H2O? (A) 106, (B) 94, (C) 92, (D) 108, (E) 120.
9. How does fructose-2,6-bisphosphate regulate gluconeogenesis? (A) It inhibits phosphofructokinase to stimulate gluconeogenesis, (B) It inhibits fructose-1,6-bisphosphatase to reduce gluconeogenesis, (C) It activates Pyruvate kinase to reduce gluconeogenesis, (D) It activates phosphofructokinase to stimulate gluconeogenesis, (E) It activates pyruvate carboxylase to stimulate gluconeogenesis.
10. Acetate units for fatty acid synthesis are activated by formation of _______.(A)Malonyl-CoA, (B) Acetyl-CoA, (C) Butyryl-CoA, (D) Malonyl-CoA and Acetyl-CoA, (E) Acetyl-CoA and Butyryl-CoA.
11. Which of the following statement about the mitochondrial electron transport chain is TRUE? (A) Complex I transfers electrons from FADH2 to ubiquinone, (B) The Q cycle mediated by Complex II reduces cytochrome c, (C) A single catalytic cycle of Complex III transports four protons from the intermembrane space to the matrix, (D) Complex IV uses electrons from cytochrome c to reduce O2 to H2O, (E) Electrons move from more positive to more negative reduction potentials.
12. In the TCA cycle (also known as the Krebs cycle), which enzyme catalyzes the formation of GTP? (A) succinyl-CoA synthetase, (B) nucleoside diphosphate kinase, (C) succinate dehydrogenase, (D)alpha-ketoglutarate debydrogenase, (E) malate dehydrogenase.
13. Glucose-6-phosphate dehydrogenase is the rate-determining enzyme of the pentose phosphate pathway. How is this enzyme regulated? (A)Activated by NADPH, (B) Activated by fatty acyl CoA, (C) Activated by NADP+, (D) Activated by ribose, (E) Activated by ADP.

14. Fatty acids are activated for β-oxidation by the hydrolysis of_______. (A) UTP to UMP, (B) UTP to UDP, (C) CTP to CMP, (D) ATP to AMP, (E) ATP to ADP.
15. Which of the following cofactor is used to transfer one-carbon units such as methyl, formyl, and methenyl groups? (A) Biotin, (B) Thiamine pyrophosphate, (C) Lipoamide, (D) FAD, (E) Tetrahydrofolate.
16. Which of the following sugar is a ketose? (A)ribose, (B) maltose, (C) glucose, (D) galactose, (E) fructose.
17. The role of cytochrome bof complex in the photosystem is analogous to the role of mitochondrial _______.(A) complex I, (B) complex II, (C) complex III, (D) complex IV, (E)complex V.
18. Which of the following cofactor requires a shuttle system in order to pass electrons to the electron transport chain? (A)NADH produced in the citric acid cycle, (B) NADH produced during glycolysis, (C) QH2 produced during fatty acid oxidation, (D) NADH produced during fatty acid oxidation, (E) all.
19._______ is the common intermediate to synthesize aromatic amino acids and cellular compounds containing benzene rings. (A) Chorismate, (B) Pristanic acid, (C) Arachidonic acid, (D) Squalene, (E) Ornithine.

20. The Lineweaver-Burk plot of an enzyme without inhibitor is shown. Which dash line can represent the kinetics of this enzyme in the presence of a competitive inhibitor? (A)(B) (C)(D)(E) 

申論題 (5)

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%)