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中国大学MOOC生物化学作业答案

生物化学

学校: 无

平台: 超星学习通

题目如下：

1. A 55-year-old British teacher presents with weight loss, weakness, muscle atrophy, and declining cognitive function. Her history reveals that her favorite meal is soup made with cow brain, which she has eaten almost every week since she was 10 years old. She is suspected to suffer from bovine spongiform encephalopathy (BSE). In comparing viruses with prions, which of the following is most likely?

A. Both prions and viruses contain some form and quantity of nucleic acid, either DNA, RNA, or both.

B. Both viruses and prions upon infection induce an antibody response in the host.

C. Both viruses and prions upon infection induce an inflammatory response in the host.

D. Conventional viruses are rapidly inactivated by ultraviolet light or heat, whereas prions are not.

E. Both viral and prion proteins

答案: Conventional viruses are rapidly inactivated by ultraviolet light or heat, whereas prions are not.

2. The oxygen carrier of muscle is the globular protein myoglobin. Which of the following amino acids is highly likely to be localized within the interior of the molecule?

A. Arginine

B. Aspartic acid

C. Glutamic acid

D. Valine

E. Lysine

答案: Valine

3. A 6-year-old African American girl with speech delay is found to have a large, abnormal peak when blood amino acids are measured. The abnormal amino acid migrates toward the cathode, indicating a positively charged side group in addition to its carboxyl and amino groups. Which of the following amino acids is most probable?

A. Alanine

B. Glycine

C. Histidine

D. Leucine

E. Valine

答案: Histidine

4. Select the one of the following statements that is NOT CORRECT :

A. Ion-exchange chromatograph separates proteins based upon the sign and magnitude of their charge at a given PH.

B. Two-dimensional gel electrophoresis separates proteins first on the basis of their PI values and second on their charge to mass ratio using SDS.

C. Affinity chromatograph exploits the selectivity of protein-ligand interactions to isolate a specific protein from a complex mixture.

D. Many recombinant proteins are expressed with an additional domain fused to their N-or C-terminals. One common component of these fusion domains is a ligand binding site designed expressly to facilitate purification by affinity chromatography.

E. Tandem mass spectrometry can analyze peptides derived from complex protein mixtures without their prior separation.

答案: Two-dimensional gel electrophoresis separates proteins first on the basis of their PI values and second on their charge to mass ratio using SDS.

5. Select the one of the following statements that is NOT CORRECT :

A. Protein folding is assisted by intervention of specialized auxiliary proteins called chaperone.

B. Protein folding tends to be modular, with areas of local secondary structure forming first, then coalescing into a molten globule.

C. Protein folding is driven first and foremost by the thermo 广东开放大学 dynamics of the water molecules surrounding the nascent polypeptide.

D. The formation of S-S bond in a mature protein is facilitated by the enzyme protein disulfide isomerase.

E. Only a few unusual proteins, such as collagen, require posttranslational processing by partial proteolysis to attain their mature conformation.

答案: Only a few unusual proteins, such as collagen, require posttranslational processing by partial proteolysis to attain their mature conformation 国家开放大学 .

6. Select the one of the following statements that is NOT CORRECT :

A. Changes in configuration involve the rupture of covalent bonds.

B. Changes in configuration involve the rotation of one or more single bonds.

C. The Ramachandran plot illustrates the degree to which steric hindrance limits the permissible angles of the single bonds in the backbone of a peptide or protein.

D. Formation of an α-helix is stabilized by the hydrogen bonds between each peptide bond carboxyl oxygen and the N-H group of the next peptide bond.

E. In a β-sheet the R-group of adjacent residues point in opposite directions relative to the plane of the sheet.

答案: Changes in configuration involve the rupture of covalent bonds.

7. Select the one of the following statements that is NOT CORRECT :

A. The Bohr effect refers to the release of protons that occurs when oxygen binds to deoxyhemoglobin.

B. Shortly after birth of the human infant synthesis of the α-chain undergoes rapid induction until it comprises 50% of the hemoglobin tetramer.

C. The β-chain in fetal hemoglobin is present throughout gestation.

D. Thalassemias are genetic defects due to partial or total absence of the α- or β-chains of hemoglobin.

E. The taut conformation of hemoglobin is stabilized by several salt bridges that form between the subunits.

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8. Consider the amino acid shown below. The configuration about which atom will determine whether the amino acid is in the D or L configuration?

A. 如图

B. 如图

C. 如图

D. 如图

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9. Which of the following amino acids are belonged to the acidic amino acids?

A. Phe Tyr

B. Met Cys

C. Leu Ile

D. Glu Asp

E. Gly Ala

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10. The covalent bond formed between the carboxyl group of one amino acid and the amino group of another amino acid is called______.

A. Phosphoester bond

B. phosphodiester bond

C. Peptide bond

D. Glycosidic bond

E. Thioester bond

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11. A part of protein sequence that can form a compact three-dimensional structure and often can be independently folded is called ______.

A. Residue

B. Secondary structure

C. Motif

D. Domain

E. Subunit

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12. Proteins are large biological molecules consist of which of the following amino acids?

A. L-α-amino acids

B. D-α-amino acids

C. L-β-amino acids

D. D-β-amino acids

E. L- and D-β-amino acids

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13. Which of the following amino acids are belonged to the basic amino acids?

A. Phe Tyr

B. Met Cys

C. Leu Ile

D. Glu Asp

E. Arg Lys

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14. Consider the followin 渝粤题库 g structure: This structure is best described as which of the following?

A. An amino acid

B. A dipeptide

C. A tripeptide

D. A tetrapeptide

E. A pentapeptide

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15. A 56-year-old pathologist was taken to his family doctor by his son for he was showing mood changes, minor loss of memory, and decreased motor skills. During the patient history, it became clear that over the course of his career he had, on occasion, cut himself using the instruments he had been using on the cadavers he had been working on. A potential explanation for his symptoms is abnormal aggregation of which of the following proteins?

A. Hemoglobin in the red blood cells

B. Collagen in the extracellular compartment of the brain

C. A truncated neuronal protein

D. A misfolded form of a normal protein

E. A truncated extracellular protein

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16. When using Biuret's test, which macromolecule will produce a positive reaction (colour change from blue to lilac)?

A. Protein

B. Fat

C. Carbohydrate

D. amino acid

E. all four

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17. A single polypeptide that assembles with other polypeptides to form a protein complex is best described as which of the following?

A. Residue

B. Secondary structure

C. Motif

D. Domain

E. Subunit

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18. How many amino acids are involved in making proteins in humans?

A. 5

B. 20

C. 35

D. 64

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19. Amino acids join up into a large chain (polymer) to create what biological molecule(s)?

A. DNA

B. Proteins

C. Bone

D. Fats

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20. The sequence of part of a DNA strand is the following: -ATTCGATTGCCCACGT-. When this strand is used as a template for DNA synthesis, the product will be which one of the following?

A. TAAGCTAACGGGTGCA

B. UAAGCUAACGGGUGCA

C. ACGUGGGCAAUCGAAU

D. ACGTGGGCAATCGAAT

E. TGCACCCGTTAGCTTA

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21. Which of these three-letter codes is correct regarding the amino acid isoleucine?

A. Ile

B. Isl

C. Iso

D. Ilc

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22. The description of the secondary structure of DNA double helix are correct, EXCEPT

A. Two antiparallel strands

B. Deoxyribose-phosphate frame located outside the strands

C. Two strands are joined by hydrogen bond formed between A-T and G-C

D. Diameter of helix is 2 nm, and 10 bases in each turn

E. Nucleosome is the structure unit of DNA double helix

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23. The correct description about Tm is

A. The temperature at which half of the maximum absorbance value of DNA at 260nm during heat denaturation

B. The temperature at which maximum absorbance value of DNA at 260nm during heat denaturation

C. The optimum temperature for DNA synthesis

D. High Tm value is related to low G-C content

E. The temperature to form DNA and RNA hybrid molecule

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24. If the coden of mRNA is ACG, then the anticoden of tRNA is

A. UGC

B. TGC

C. GCA

D. CGU

E. TGC

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25. The linkage between nucleotides is

A. 2’,-3’ phosphodiester bond;

B. 3’,-5’ phosphodiester bond

C. 2’,-5’ phosphodiester bond;

D. Hydrogen bond

E. Peptide bond

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26. The template strand of DNA is 5’-ATTCAG-3 ’ , its transcript is

A. 5’ -GACTTA-3’

B. 5’ -CTGAAT-3’

C. 5’ -UAAGUC-3’

D. 5’ -CUGAAU-3’

E. 5’ - TAAGTC-3’

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27. While studying the structure of a small gene that was recently sequenced during the Human Genome Project, an investigator notices that one strand of the DNA molecule contains 20A’s, 25G’s, 30C’s and 22T’s,how many of each base is found in the complete double-stranded molecule?

A. A=40, G=50, C=60, T=44

B. A=44, G=60, C=50, T=40

C. A=45, G=45, C=52, T=52

D. A=50, G=47, C=50, T=47

E. A=42, G=55, C=55, T=42

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28. All of the following are true of the differences between DNA and RNA except:

A. RNA utilizes uracil (U) in place of thymine (T).

B. RNA has a 2'-OH whereas DNA does not.

C. The nucleotides in DNA are linked 3'-5' by phosphodiester bonds but in RNA they are linked 2'-5'.

D. DNA is usually double stranded and RNA is usually single stranded.

E. There is more RNA than DNA in the cell.

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29. DNA secondary structure is a right-handed double helix with a sugar phosphate backbone on the outside and paired bases (A-T, G-C) on the inside. Which of the following are true?

A. The two strands are parallel.

B. Van der Waal's forces between stacked bases destabilizes the structure.

C. The two strands are antiparallel.

D. A, B, and Z-DNA forms are present in nature.

E. Only the B-DNA form is present

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30. The hyperchromic effect refers to the increase in the UV absorption of DNA. This is a result of:

A. Annealing

B. Melting of DNA

C. B to Z-DNA conversion.

D. Increased hydrogen bonding between strands.

E. Renaturation of DNA

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31. RNA also has some structure. These include all of the following except:

A. Hairpin turns

B. Internal loops and bulges

C. beta-helix

D. Right-handed double helix

E. Cloverleaf structure

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32. In order to package the 3x109 nucleotides of DNA into the nucleus, the DNA is wound around histones. These are proteins that bind to the DNA. The interaction of histones and DNA involves:

A. AT, GC pairing between histones and DNA

B. H-bonding between arginine and lysine residues and the DNA phosphate backbone

C. Basic residues of the histone and the phosphate backbone of DNA

D. Proteolysis

E. hydrophobic interaction

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33. Small snRNPs are involved in:

A. Translation

B. mRNA processing

C. Transcription

D. Catalysis of peptide bonds

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34. The core proteins in nucleosome are

A. H2A, H2B, H3, H4.

B. H1A, H1B, H3, H4.

C. H1A, H2A, H3, H4.

D. H1, H2, H3, H4.

E. H2A, H2B, H1, H2.

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35. A 50-year-old man has been trying to lose weight, but he enjoyed eating so much that he found it difficult to do so .He then reads about a product in the popular press, which guarantees that he can lose weight ,as caloric intake due to starch ingestion will be reduced ( a starch blocker). The over-the-counter product that he buys is claimed to inhibit which of the following enzymes?

A. Pancreatic trypsinogen

B. Pancreatic lipase

C. salivary amylase

D. Gastric amylase

E. Intestinal enteropeptidase

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36. Routine newborn screening identified a child with elevated levels of α-ketoacids of the branched-chain amino acids. A certain subset of such children will respond well to which of the following vitamin supplementation?

A. Niacin

B. Riboflavin

C. B12

D. B6

E. Thiamine

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37. deficiency in which of the following vitamins will lead to a functional folate deficiency?

A. Thiamine

B. Niacin

C. Riboflavin

D. 成人学历 B12

E. Vitamin C

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38. 关于酶抑制剂的叙述正确的是：

A. 酶的抑制剂中是酶的变性剂

B. 酶的抑制剂只与活性中心上的基团结合

C. 酶的抑制剂均能使酶促反应速度下降

D. 酶的抑制剂一般是大分子物质

E. 酶的抑制剂都能竞争性地使酶的活性降低

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39. 泛酸是下列哪种生化反应中酶所需辅酶成分?

A. 脱羧作用

B. 脱氢作用

C. 还原作用

D. 乙酰化作用

E. 氧化作用

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40. A newborn has milky white skin, white hair, and red-appearing eye color (see the figure below).This disorder most often results from a defect in which of the following enzymes

A. Phenylalanine

B. NADPH oxidase

C. Dihydrofolate

D. Tyrosinase

E. Homogentisic acid oxidase

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41. In a laboratory study, volunteers were made experimentally vitamin B6 deficient, and much to the investigator’s surprise, a mild hypoglycemia, with ketosis, was noted. The hypoglycemia is a result of which of the following?

A. Inhibition of phosphoenolpyruvate carboxykinase

B. Inhibition of pyruvate carboxylase

C. Reduced activity of glucose-6-phosphatase

D. Reduced activity of liver glycogen phosphorylase

E. Reduced insulin secretion

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42. 为了防止酶失活，最好将酶制剂存放于以下什么条件

A. 0℃避光

B. 室温曝光

C. 室温避光

D. 最适温度

E. 80℃以上

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43. 乳酸脱氢酶属于：

A. 转移酶类

B. 水解酶类

C. 氧化还原酶类

D. 异构酶类

E. 裂解酶类

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44. 在离体线粒体实验中测得一底物的P/O比值是1.8，该底物脱下的氢最有可能在下列哪一部位进入呼吸链

A. NAD+

B. FMN

C. cytc1

D. cytaa3

E. 以上都不对

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45. 酶原激活的生理意义是：

A. 加速代谢

B. 恢复酶活性

C. 促进生长

D. 避免自身损伤

E. 保护酶的活性

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46. 下列关于Km值的描述哪一项是错误的？

A. 是酶的特征性常数

B. 近似表示酶催化底物转变为产物的能力

C. 对于不同的底物有不同的Km值

D. 不因酶浓度的改变而改变

E. 不因底物浓度的改变而改变

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47. 酶原缺乏活性的主要原因是：

A. 肽链合成时缺少某些肽段

B. 活性中心未形成

C. 未结合辅酶

D. 缺乏必需激活剂

E. 存在特定的抑制剂

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48. 下列有关温度对酶反应速度影响的叙述中，错误的是：

A. 温度对酶促反应速度的影响不仅包括升高温度使速度加快，也同时会使酶逐步变性

B. 在一定的温度范围内，在最适温度时，酶反应速度最快

C. 最适温度是酶的特征常数

D. 最适温度不是一个固定值，而与酶作用时间长短有关

E. 一般植物酶的最适温度比动物酶的最适温度稍高

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49. 关于酶的激活剂的叙述错误的是：

A. 激活剂可能是无机离子，中等大小有机分子和具蛋白质性质的大分子物质

B. 激活剂对酶不具选择性

C. Mg2+是多种激酶及合成酶的激活剂

D. 作为辅助因子的金属离子不是酶的激活剂

E. 激活剂可使酶的活性提高

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50. Select the one FALSE statement:

A. Marfan syndrome is due to m 渝粤教育 utations in the gene encoding fibrillin-1, a major constituent of microfibrils.

B. All cases of Ehlers–Danlos syndrome are due to mutations affecting the genes encoding the various types of collagen.

C. Laminin is found in renal glomeruli along with entactin, type IV collagen, and heparin or heparan sulfate.

D. Mutations affecting type IV collagen can cause serious renal disease.

E. Mutations in the collagen 1A1 gene can cause osteogenesis imperfecta.

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51. Regarding the ABO blood group substances, select the one FALSE statement:

A. They can be either glycosphingolipids or glycoproteins, depending on location.

B. Individuals with blood group AB have antibodies to both A and B blood group substances.

C. Blood group H substance is formed from its precursor by the action of a fucosyltransferase.

D. Blood group B is formed from its precursor by the action of a galactosyltransferase.

E. Individuals of blood group O lack the galactosyltransferase.

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52. A male infant is failing to thrive and, on examination, is noted to have hepatomegaly and splenomegaly, among other findings. Urinalysis reveals the presence of both dermatan sulfate and heparan sulfate. You suspect the patient has Hurler syndrome. From the following list, select the enzyme that you would wish to have assayed to support your diagnosis:

A. -Glucuronidase.

B. -Galactosidase.

C. -L-Iduronidase

D. -N-Acetylglucosaminidase

E. Neuraminidase

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53. All of the following sugars are found in glycoproteins EXCEPT:

A. Fructose

B. Fucose

C. Galactose

D. Mannose

E. Xylose

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54. Select the one FALSE statement:

A. Mucins contain predominantly O-linked glycans.

B. O-linked sugar chains are built up by the stepwise donation of sugars from nucleotide-sugars.

C. Dolichol-pyrophosphate–oligosaccharide donates all of the sugars found in mature N-linked glycoproteins.

D. N-acetylneuraminic acid is commonly found at the termini of N-linked sugar chains.

E. Calnexin retains partly folded or misfolded proteins in the ER until proper folding has occurred.

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55. 以下说法错误的是：

A. 糖蛋白和蛋白聚糖都是由糖与蛋白质两部分由共价键连接组成。

B. 组成蛋白聚糖的糖链称为糖胺聚糖

C. 组成糖蛋白的糖链可分为N-糖链和O-糖链

D. 一般来说，糖蛋白分子中的蛋白质百分比小于糖，而蛋白聚糖则相反

E. 组成糖蛋白和蛋白聚糖中的糖链结构迥然不同，功能也有差异

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56. 鞘糖脂的分子组成包括：

A. 甘油

B. 鞘氨醇

C. 磷酸

D. 糖链

E. 脂肪酸

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57. 体内重要的糖胺聚糖有：

A. 硫酸软骨素

B. 硫酸角质素

C. 肝素

D. 硫酸皮肤素

E. 透明质酸

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58. 以下说法正确的是：

A. 糖蛋白和蛋白聚糖都是由糖与蛋白质两部分由共价键连接组成。

B. 组成蛋白聚糖的糖链称为糖胺聚糖

C. 组成糖蛋白的糖链可分为N-糖链和O-糖链

D. 一般来说，糖蛋白分子中的蛋白质百分比小于糖，而蛋白聚糖则相反

E. 组成糖蛋白和蛋白聚糖中的糖链结构迥然不同，功能也有差异

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59. 在N-连接糖蛋白中，N-糖链主要存在以下哪几种亚型？

A. 高甘露糖亚型

B. 低甘露糖亚型

C. 复杂亚型

D. 简单亚型

E. 杂合亚型

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60. Which one of the following statements concerning glycolysis is correct?

A. The conversion of glucose to lactate requires the presence of oxygen.

B. Hexokinase is improtant in hepatic glucose metabolism only in the absorptive period following consumption of a carbohydrate-containing meal.

C. Fructose 2,6-bisphosphate is a potent inhibitor of phosphofructokinase.

D. The rate-limiting reactions are also the irreversible reaction.

E. The conversion of glucose to lactate yields two ATP and two NADH

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61. Which one of the following is a condition decreased the oxidation of acetyl CoA by the citric acid cycle?

A. A low ATP/ADP ratio

B. A low NADH due to rapid oxidization to NAD+ through the respiratory chain

C. A low NAD+/NADH ratio

D. A high concentration of AMP

E. A low GTP/GDP ratio

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62. The synthesis of glucose from pyruvate by gluconeogenesis:

A. occurs exclusively in the cytosol.

B. is inhibited by an elevated level of glucagon.

C. requires the participation of biotin.

D. involves lactate as an intermediate.

E. requires the oxidation/reduction of FAD.

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63. A two year-old boy was brought into the emergency room, suffering from severe fasting hypoglycemia. On physical examination, he was found to have hepatomegaly. Laboratory tests indicated that he also had hyperlacticacidemia and hyperuricemia. A liver biopsy indicated that hepatocytes contained greater than normal amounts of glycogen that was of normal structure. The child was subsequently found to be missing which of the following enzymes?

A. Glycogen synthase

B. Glycogen phosphorylase

C. Glucose 6-phosphatase

D. Amylo-α (1→ 6)-glucosidase

E. Amylo-α (1→ 4) → α (1→ 6)-transglucosylase

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64. Epinephrine and glucagon have which one of the following effects on glycogen metabolism in the liver?

A. The net synthesis of glycogen is increased.

B. Glycogen phosphorylase is activated, whereas glycogen synthase is inactivated.

C. Both glycogen phosphorylase and glycogen synthase are activated but at significantly different rates.

D. Glycogen phosphorylase is inactivated, whereas glycogen synthase is activated.

E. cAMP-dependent protein kinase is activated, whereas phosphorylase kinase is inactivated.

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65. Most of the reducing equivalents utilized for synthesis of fatty acids can be generated from

A. The pentose phosphate pathway

B. Glycolysis

C. The citric acid cycle

D. Mitochondrial malate dehydrogenase

E. Citrate lyase

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66. Which coenzyme in pyruvate dehydrogenase complex serves as the final hydrogens acceptor?

A. FAD

B. lipoate

C. NAD+

D. TPP

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67. The degradation of glycogen normally produces

A. more glucose than glucose l-phosphate

B. more glucose 1-phosphate than glucose

C. equal amounts of glucose and glucose 1-phosphate

D. neither glucose nor glucose l-phosphate

E. only glucose l-phosphate

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68. In which compartment of the cell does glycolysis occur?

A. Mitochondrion

B. Nucleus

C. Soluble cytoplasm (cytosol)

D. Rough endoplasmic reticulum

E. Smooth endoplasmic reticulum

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69. How many net molecules of ATP are generated in the conversion of glucose to pyruvate?

A. 0

B. 1

C. 2

D. 3

E. 4

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70. Which of the following statements about glycolysis is TRUE?

A. Glucokinase catalyzes the conversion of glucose to glucose 6-phosphate in the liver

B. Phosphofructokinase 1 catalyzes the conversion of fructose 1,6-bisphosphate to dihydroxyacetone phosphate

C. When one molecule of glucose is converted to pyruvate via glycolysis, one molecule of NADH is reduced

D. When one molecule of glucose is converted to pyruvate via glycolysis, one carbon is lost as CO2

E. Hexokinase catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate

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71. NADH is required for the one-step reaction by which pyruvate is converted to

A. oxaloacetate

B. acetyl CoA

C. phosphoenolpyruvate

D. lactate

E. none of them

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72. Which of the following glycolytic enzymes is used in gluconeogenesis?

A. Glucokinase

B. Phosphofructokinase 1

C. Pyruvate kinase

D. Aldolase

E. None of them

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73. An infant with an enlarged liver has a glucose 6-phosphatase deficiency. This infant

A. cannot maintain blood glucose levels either by glycogenolysis or by gluconeogenesis

B. can use liver glycogen to maintain blood glucose levels

C. can use muscle glycogen to maintain blood glucose levels

D. can convert both alanine and glycerol to glucose to maintain blood glucose levels

E. none of them

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74. The pentose phosphate pathway generates each of the following products EXCEPT

A. NADPH, which may be used for fatty acid synthesis

B. ribose 5-phosphate, which may be used for the biosynthesis of ATP

C. compounds that are intermediates of glycolysis

D. D.xylulose 5-phosphate by one of the nonoxidative reactions

E. glucose from ribose 5-phosphate and CO2

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75. The unique pathway for mature red blood cells to obtain ATP is

A. pentose phosphate pathway

B. tricarboxylic acid cycle

C. β-oxidation of fatty acid

D. glycolysis

E. gluconeogenesis

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76. Which enzyme is the key enzyme in glycogenolysis (glycogen degradation) ?

A. Phosphorylase

B. Hexokinase

C. Phosphoenol pyruvate carboxykinase

D. HMG-CoA reductase

E. Pyruvate kinase

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77. Which of the following metabolic pathway take place in the mitochondira?

A. A.glycolytic pathway

B. the synthesis of ketone body

C. pentose phosphate pathway

D. the synthesis of the fatty acid

E. the synthesis of the glycogen

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78. The principl function of the TCA cycle is to

A. generate CO2

B. transfer electrons from the acetyl portion of acetyl CoA to NAD+ and FAD

C. oxidize the acetyl portion of acetyl CoA to oxaloacetate

D. generate heat from the oxidation of the acetyl portion of acetyl CoA

E. dispose of excess pyruvate and fatty acids

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79. The compound which can not be converted into glucose is in animals.

A. lactate

B. pyruvate

C. glycerol

D. fatty acid

E. glycine

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80. The electron transport chain is made up of four segments (Complexes I-IV with O2 as the final electron acceptor). Which statement best describes the electron transport chain

A. Each component involves a phosphorylation step.

B. Each complex directly transfers electrons to O2.

C. Electrons flow spontaneously from one carrier to the next.

D. Fe-S cluster acts as a important coenzyme in complex.

E. Locate in outer membrane of mitochondria

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81. Why does the oxidation of NADH lead to roughly 3 ATPs, while FADH2 oxidation produces only about 2 ATPs?

A. FADH2 enters the electron transport chain later than NADH.

B. The 2 hydrogens in FADH2 go directly to the synthesis of 2 ATPs.

C. More NADH is produced during metabolism.

D. FADH2 is only important in fatty acid oxidation.

E. Redox potential change is only sufficient for production of 2 ATPs.

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82. Which of following subunit is mainly responsible to catalyze the synthesis of ATP in ATP synthase?

A. α

B. β

C. γ

D. ε

E. c

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83. What is the consequence of thermalgenin effect.

A. Producing more heat

B. ETC is inhibited

C. Producing more ATP

D. Oxidative phosphorylation is increased

E. None of the above

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84. A research was studying oxidative phosphorylation in a suspention of carefully washed and isolated mitochondria ATP, ADP, inorganic phosphate, lactate, lactate dehydrogenase, and oxygen were introduced to the suspension, and he was able to demonstrate ATP production within the mitochondria.The research we then added oligomycin to the mixture, which stopped oxygen uptake. This occurred due to which of the following?

A. Inhibition of complex Ⅰ

B. Inhibition of complex Ⅱ

C. Inhibition of complex Ⅲ

D. Inhibition of complex Ⅳ

E. Inhibition of the proton translocating ATPase

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85. The electron transport chain is made up of four segments (Complexes I-IV with O2 as the final electron acceptor). Which statement best describes the electron transport chain?

A. Each component involves a phosphorylation step.

B. Each complex directly transfers electrons to O2.

C. Electrons flow spontaneously from one carrier to the next.

D. Every complex has a Fe-S cluster.

E. Locate in outer membrane of mitochondria

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86. 关于生物氧化的描述哪一项是错误的？

A. 一系列酶参与催化

B. 反应条件较温和

C. CO2与反应物中的

D. 释放的能量部分储存在高能化合物中

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87. 下列化合物中除( )外都是呼吸链的组成成分。

A. CoQ

B. Cytb

C. CoA

D. NAD+

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88. 线粒体中跨膜质子浓度梯度建立后是

A. 线粒体内膜内侧的质子浓度高于外侧的质子浓度

B. 线粒体内膜外侧的质子浓度高于内侧的质子浓度

C. 线粒体外膜内侧的质子浓度高于外侧的质子浓度

D. 线粒体外膜外侧的质子浓度高于内侧的质子浓度

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89. 线粒体外NADH经α-磷酸甘油穿梭作用，进入线粒体内实现氧化磷酸化，其p/o值为

A. 0

B. 1.5

C. 2.5

D. 3.5

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90. Which one of the following statements about the absorption of lipids from the intestine is correct?

A. Dietary triacylglycerol is partially hydrolyzed and absorbed as free fatty acids and monoacylglycerol.

B. Dietary triacylglycerol must be completely hydrolyzed to free fatty acids and glycerol before absorption.

C. Release of fatty acids from triacylglycerol in the intestine is inhibited by bile salts.

D. Fatty acids that contain ten carbons or less are absorbed and enter the circulation primarily via the lymphatic system.

E. Formation of chylomicrons does not require protein synthesis in the intestinal mucosa

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91. The rate-limting enzyme in the β-oxidation of fatty acid is

A. acyl CoA synthetase

B. carnitine acyltransferase I

C. carnitine acyltransferase II

D. acyl CoA dehydrogenase

E. hydroxyacyl CoA dehydrogenase

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92. In liver, large numbers of acetyl CoA derived from fat mobilization convert mainly into

A. glucoses

B. cholesterols

C. fatty acids

D. ketone bodies

E. cholesterol esters

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93. Rate-limiting enzyme in the synthesis of ketone bodies is

A. thiolase

B. HMG-CoA synthase

C. HMG-CoA lyase

D. β-hydroxybutyrate dehydrogenase

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94. The compound which can not be oxidized into CO2 and H2O in vivo is

A. acetoacetate

B. lactate

C. glycerol 3-phosphate

D. cholesterol

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95. The activated choline required for the lecithin biosynthesis is

A. ADP- choline

B. CDP- choline

C. GDP- choline

D. UDP- choline

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96. Which is the following can transfer acetyl group from mitochondria to cytoplasm

A. Acetyl-CoA

B. Acetyl-carnitine

C. Succinate

D. Citric acid

E. Oxaloacetate

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97. After they are produced from acetyl-CoA in the liver, ketone bodies are mainly used for which one of the following processes?

A. Excretion as waste products.

B. Energy generation in the liver.

C. Conversion to fatty acids for storage of energy.

D. Generation of energy in the tissues.

E. Generation of energy in red blood cells.

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98. The class of drugs called statins have proved very effective against hypercholesterolemia, a major cause of atherosclerosis and associated cardiovascular disease. These drugs reduce plasma cholesterol levels by:

A. Preventing absorption of cholesterol from the intestine.

B. Increasing the excretion of cholesterol from the body via conversion to bile acids.

C. Inhibiting the conversion of 3-hydroxy-3-methylglutaryl-CoA to mevalonate in the pathway for cholesterol biosynthesis.

D. Increasing the rate of degradation of 3-hydroxy-3-methylglutaryl CoA reductase.

E. Stimulating the activity of the LDL receptor in the liver.

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99. Which one of the following statements concerning chylomicrons is CORRECT?

A. Chylomicrons are made inside intestinal cells and secreted into lymph, where they acquire apolipoproteins B and C.

B. The core of chylomicrons contains triacylglycerol and phospholipids.

C. The enzyme hormone sensitive lipase acts on chylomicrons to release fatty acids from triacylglycerol when they are bound to the surface of endothelial cells in blood capillaries.

D. Chylomicron remnants differ from chylomicrons in that they are smaller and contain a lower proportion of triacylglycerol.

E. Chylomicrons are taken up by the liver.

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100. The subcellular site of the breakdown of long chain fatty acids to acetyl-CoA via -oxidation is:

A. The cytosol

B. The matrix of the mitochondria

C. The endoplasmic reticulum

D. The mitochondrial intermembrane space

E. E.The Golgi apparatus

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101. You are examining a patient who exhibits fasting hypoglycemia and need to decide between a carnitine deficiency and a carnitine acyltransferase 2 deficiency as the possible cause. You order a blood test to specifically examine the levels of which one of the following?

A. Glucose

B. Ketone bodies

C. Insulin

D. Acyl-carnitine

E. Carnitine

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102. Under condition of starvation, the major fuel for the brain is

A. blood glucose

B. fatty acids

C. ketone bodies

D. amino acids

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103. A patient presents in your office with very high levels of serum cholesterol. After a series of tests, you conclude that the patient has high circulating levels of LDL cholesterol, but has normal levels of the liver LDL receptor. One possible explanation for this observation is which of the following?

A. The patient has a mutated form of apoprotein B-100.

B. The inability to selectively remove cholesterol from the LDL complex.

C. The absence of the enzyme lipoprotein lipase.

D. Decreased levels of acyl-CoA: cholesterol acyltransferase

E. Altered phosphorylation of the LDL receptor.

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104. A patient presents in your office with very high levels of serum cholesterol. He states that he has tried to follow the diet and exercise regimen you gave him last year. You decide that this patient would benefit from a drug such as Lipitor (atorvastatin). This class of drugs is effective in treating hypercholesterolemia because it has what effect?

A. A.Stimulates phosphorylation of the β-hydroxyl-β-methylglutaryl-CoA reductase enzyme

B. Decrease the stability of theβ-hydroxyl-β-methylglutaryl-CoA reductase protein

C. Binds cholesterol preventing it from being absorbed by the intestine

D. Directly prevents the deposition of cholesterol on artery walls

E. Inhibits the enzymeβ-hydroxyl-β-methylglutaryl-CoA reductase

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105. Synthesis of fatty acids occurs in the cytoplasm, and is catalyzed by fatty acid synthase. In animals, fatty acid synthase is a homodimer, with each chain approximately 250,000 Daltons in size. The two chains are linked head to tail. All of the components of fatty acid synthase, including acyl carrier protein (ACP) and β-ketoacyl ACP synthase, are contained within the two chains. Reactions occur in the space between the two chains, an arrangement that keeps the reactants in one place. The first round of synthesis produces a 4-carbon unit. From here, two carbons are added until the final product, palmitate is made. How many rounds does it take to make palmitate?

A. 14

B. 10

C. 7

D. 2

E. Cannot be determined

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106. All of the following are derived from cholesterol except:

A. Bile salts

B. Progesterone

C. Glucocorticoids

D. Squalene

E. Mineralocorticoids

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107. In humans, obesity is not caused by leptin levels, but by malfunctioning signal mechanisms. Which of the following do you think might be affected by high leptin concentrations binding to receptor?

A. Activation of acetyl CoA to malonyl CoA

B. Lipase

C. Phosphate pentose pathway

D. Cholesterol synthesis

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108. A 7-year-old girl has 1 1-month history of foul-smelling diarrhea. Upon further inquiry, the frequency seems to be 4-6 stools per day. She has also had trouble seeing at night in the past2 weeks. Her WBC count is normal. Physical examination is entirely normal. Examination of a stool sample reveals that it is bulky and greasy. Analysis does not reveal any pathogenic microorganisms or parasites but confirms the presence of fats. Further evaluation of this patient would likely reveal which of the following conditions?

A. Lactose intolerance

B. Biliary insufficiency

C. Ileal disease

D. Diabetes

E. Giardiasis

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109. A 19-year-old man complains of “brown urine” and pain in the muscles of his arms and legs experienced while playing touch football. He has had several episodes of muscle pain during exercise, but he had not noticed darkening of his urine afterward. The pain usually resolved overnight. Physical examination reveals a well-fed male of normal stature. Reflexes and range of motion in all arms and legs are normal, but there is some paraparesis (weakness), especially in his right leg. A muscle biopsy is taken and sent for specialized resting. The patient is sent home with a recommendation to take a dietary carnitine supplement. Which of the following is the most likely diagnosis?

A. Medium-chain fatty acyl CoA dehydrogenase (MCAD) deficiency

B. Carnitine deficiency

C. Carnitine palmitoyltransferases I deficiency

D. Carnitine palmitoyltransferases II deficiency

E. Marfan syndrome

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110. A newborn infant had trouble breathing at birth. The infant was 3 months premature. The physicians treated the infant with a solution, which was directly injected into the lungs. Within seconds, the infant responded with much improved breathing. A major component of this solution is which one of the following?

A. Dipalmitoyl phosphatidylcholine

B. Palmitate containing ceramide

C. Sphingosine

D. Sphingomyelin

E. Diacylgylycerol

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111. In the presence of hyperammonia, production of which of the following amino acids is always increased?

A. Glycine

B. Arginine

C. Proline

D. Histidine

E. Glutamine

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112. The primary manner for the deamination of amino acids in muscle involves.

A. purine nucleotide cycle

B. oxidative deamination of glutarate

C. transamination

D. ornithine cycle

E. conjunction of transamination and oxidative deamination

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113. The major fate of ammonia is ( ) in the body.

A. to synthesize nonessential amino acids

B. to synthesize glutamine

C. to synthesize urea

D. to synthesize alanine

E. to synthesize nucleotides

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114. Which of the following are the nitrogen source of urea ?

A. carbomoyl phosphate and aspartate

B. carbomoyl phosphate and ornithine

C. α-amino group and γ-amino group of ornithine

D. α-amino group of citrulline and α-amino group of arginine

E. γ-amino group of ornithine and glycine

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115. Which of the following amino acids can be converted into taurine in the body?

A. Cysteine

B. Glycine

C. Methionine

D. Threonine

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116. The compound which does not belong to one carbon unit as follow is.

A. -CH3

B. =CH2

C. =CH-

D. CO2

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117. Which of the following is the carrier of one carbon unit ?

A. biotin

B. SAM

C. FH4

D. FH2

E. folic acid

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118. The most important role of S-adenosyl methionine (SAM) is.

A. to provide methionine

B. to synthesize tetrahydrofolate

C. to synthesize purine nucleotides

D. to synthesize pyrimidine nucleotides

E. to supply methyl group

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119. Which of the following state is nitrogen equilibrium?

A. advanced cancer patient

B. pregnant women

C. patient recovering from illness

D. people suffer form long-time hunger

E. normal adult

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120. Which of the following amino acid can not produce one carbon unit?

A. Serine

B. Valine

C. Tryptophan

D. Histidine

E. Glycine

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121. The transportation form of ammonia in blood is

A. Glutamate

B. Tyrosine

C. Glutamine

D. Glutathionine

E. Aspartate

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122. Which of the following state is positive nitrogen balance?

A. advanced cancer

B. pregnant women

C. people suffer from fever

D. people suffer form long-time hunger

E. normal adult

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123. Which of the following is not produced by Tyr?

A. norepinephrine

B. epinephrine

C. dopamine;

D. Phe

E. melanin

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124. Which of the following is the main deamination style in the body?

A. oxidation deamination

B. reduction deamination

C. direct deamination

D. transamination;

E. union deamination

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125. Which of the following amino acid can produce PAPS?

A. taurine

B. methionine

C. cysteine

D. homocysteine

E. glutamate

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126. Which of the following is the process that transport ammonia from muscle to liver?

A. TAC cycle

B. ornithine cycle

C. alanine-glucose cycle

D. methionine cycle

E. γ-glutamyl cycle

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127. Which one of the following amino acids is essential in the human diet?

A. Serine

B. Lysine

C. Glutamate

D. Tyrosine

E. Cysteine

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128. When compared to his state after an overnight fast, a person who fasts for 1 week will have

A. higher levels of blood glucose

B. less muscle protein

C. more adipose tissue

D. lower levels of ketone bodies in the blood

E. none of the above

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129. Which of the following is the direct donor of CH3?

A. N5-CH3-FH4

B. SAM

C. N5,N10- CH2-FH4

D. N5,N10=CH-FH4

E. FAD

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130. Mr Smith had been prescribed a drug to treat his depression. One of the effects of the drug is to maintain elevated levels of a particular neurotransmitter that has been derived from which of the following amino acids?

A. Tryptophan

B. Tyrosine

C. Glutamate

D. Histidine

E. Glycine

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