生物化学（英文版）期末答案2023秋

1.Regarding the narrative of the respiratory chain, which one is correct ?
A:The function structure of CoQ is an isoxazine ring. B:After uncoupling, the respiratory chain cannot deliver electrons. C:Enzymes and coenzymes are arranged in a certain order D:The meeting point of the two respiratory chains is Cytc E:Complex II participates in the formation of two respiratory chains
答案:AI参考:正确答案是C:Enzymes and coenzymes are arranged in a certain order 。\n\n该问题考查了呼吸链的叙述，涉及到氧化磷酸化中的关键环节。关于呼吸链的结构，酶和辅酶按照一定的顺序排列，这是正确的。选项A关于辅酶Q的结构错误；选项B关于解偶联剂的作用错误；选项D关于两个呼吸链的交汇点错误；选项E关于复合体II参与形成两个呼吸链的说法也不准确。因此，只有选项C是正确的。'
2.An important product of the oxidation of the body’s major energy source to provide energy for gluconeogenesis regulates which of the following key gluconeogenic enzymes?
A:PEPCK B:Glucose-6-phosphatase C:Pyruvate carboxylase D:Fructose-1,6-bisphosphatase E:Pyruvate kinase
答案:AI参考:正确答案是C:Pyruvate carboxylase。\n题目中提到一种将身体主要能量来源氧化以提供糖异生所需能量的重要产物，而Pyruvate carboxylase（丙酮酸羧化酶）是一种关键的糖异生酶，因此选项C是正确答案。其他选项如PEPCK（磷酸烯醇式丙酮酸羧激酶）、葡萄糖-6-磷酸酶、磷酸甘油酸激酶、果糖-1，6-二磷酸酶等都与糖异生过程相关，但不如丙酮酸羧化酶关键。'
3.The active form of Vitamin D is（ ）
A:1,24,25-(OH)3D3 B:25-(OH)D3 C:1,25-(OH)2D3 D:24,25-(OH)2D3
答案:AI参考:正确答案是【C:1,25-(OH)2D3】。\n\n维生素D在人体内需要经过两次羟化反应才能转化为活性形式，第一次羟化发生在C-20位上，第二次羟化发生在C-25位上，而题目中给出的选项中只有C选项符合这个条件，因此C选项是正确答案。其他选项中，A选项含有三个羟基，B选项含有两个羟基，D选项含有两个羟基和一个甲基，这些都不符合维生素D的活性形式要求。'
4.Which do not participate in constitutes DNA?
A:dCMP B:dAMP C:dGMP D:dUMP E:dTMP
答案:AI参考:正确答案是B:dAMP。\n\nDNA的基本组成单位是脱氧核糖核苷酸，其中含有磷酸、脱氧核糖和四种含氮碱基，分别是腺嘌呤脱氧核苷酸、鸟嘌呤脱氧核苷酸、胸腺嘧啶脱氧核苷酸和胞嘧啶脱氧核苷酸。其中，只有dAMP（腺嘌呤脱氧核苷酸）参与DNA的构成，其他选项中的dCMP、dGMP、dUMP和dTMP都不是DNA的构成成分。因此，答案是B。'
5.The majority of energy for muscular contraction is stored in muscle tissue in the form of
A:ADP B:ATP C:Creatine phosphate D:Cyclic AMP E:Phosphoenolpyruvate
答案:AI参考:正确答案是B:ATP。\n\n肌肉收缩所需的能量大部分以ATP的形式储存在肌肉组织中。ADP是腺苷酸，不是能量储存形式。Creatine phosphate是肌酸磷酸，是一种缓冲物质，不是能量储存形式。Cyclic AMP是环腺苷酸，是第二信使，不是能量储存形式。Phosphoenolpyruvate是磷酸烯醇丙酮酸，是糖酵解过程中的一种中间产物，不是能量储存形式。因此，答案为B，即ATP。'
6.The tissue which used salvage synthesis pathway as the main pathway to synthesize the purine nucleotides
A:liver B:skeletal muscle C:cardiac muscle D:kidney E:bone marrow
答案:AI参考:正确答案是E：bone marrow。\n骨髓中含有大量的造血干细胞，它们能利用补救合成途径为主途径合成嘌呤核苷酸，而嘌呤核苷酸是合成DNA所必需的物质，因此骨髓具有强大的合成DNA的能力。故答案为E，骨髓。'
7.The net gain per molecule of stearic acid oxidation is ATPs
A:122 B:120 C:106 D:128 E:108
答案:AI参考:正确答案是C：106。\n\n每个硬脂酸分子氧化的净结果是产生106个ATP。因此，答案为C。'
8.Which of the following enzymes is unnecessary for DNA replication?
A:Restriction endonuclease B:helicases C:DNA ligase D:DNA-dependent DNA polymerase E:Topoisomerases
答案:AI参考:正确答案是D:DNA-dependent DNA polymerase (DNA依赖性DNA聚合酶)。\n\nDNA复制过程中需要依赖DNA聚合酶进行DNA链的延伸，而限制性内切酶、解旋酶、DNA连接酶和拓扑异构酶都是DNA复制过程中的辅助酶，与DNA复制无关。因此，选项D中的DNA-dependent DNA polymerase是不需要参与DNA复制的酶。'
9.The amino acids that provide one carbon unit in the body are（ ）
A:Leucine B:Histidine C:Tryptophan D:Glycine
答案:AI参考:选项中的tryptophan是体内提供一碳单位的氨基酸，所以正确选项是C:Tryptophan。'
10.The nature of the enzyme is（ ）
A:High catalytic efficiency B:Activity can be adjusted C:Enzymatic reaction has no side reactions D:High stability E:High degree of specificity
答案:AI参考:正确选项为：A, D, E\n\n酶的本质是高催化效率的蛋白质，其特性还包括：稳定性高（D对）、具有高度的特异性（E对）和酶反应中不发生副反应。其中A选项和D选项相呼应，表达的都是酶的催化效率高。因此，本题的正确选项为A:高催化效率 和 D:稳定性高（酶）、E:高度特异性。B、C选项在酶的性质描述中并未涉及。'
11.The linkage between nucleotides is（ ）
A:Peptide bond B:2’,-5’ phosphodiester bond C:3’,-5’ phosphodiester bond D:Hydrogen bond E:2’,-3’ phosphodiester bond
答案:3’,-5’ phosphodiester bond
12.the sequence of cytochrome in respiratory chain is :
A:b ---- c ---- c1 ----aa3----O2 B:c---- b ---- c1 ----aa3----O2 C:b ----c1---- c ----aa3----O2 D:c----c1----b----aa3----O2 E:c1---- c ----b----aa3----O2
答案:b ----c1---- c ----aa3----O2
13.The formation of deoxyribonucleotide
A:by reduction reaction from NDP B:by reduction reaction from nucleoside C:by reduction reaction from NTP D:by reduction reaction from ribose E:by reduction reaction from nucleotide
答案:by reduction reaction from NTP
14.The main fate for cholesterol is
A:be converted to Vitamin D3 B:be converted to steroid hormones C:be converted to bile acid D:be converted to cholesterol ester E:be converted to fatty acids
答案:be converted to bile acid
15.A pair of farm workers in Mexico was spraying pesticide on crops when they both developed the following severe symptoms :heavy ,labored breathing, significantly elevated temperature , and loss of consciousness . The pesticide contained an agent that intertered with oxidative phosphorylation , which most closely resembled which of the following known inhibitors?
A:CO B:Oligomycin C:Cyanide D:Atractyloside E:Dinitrophenol
答案:in
16.Organic phosphorus pesticides（ ）
A:can be bind to the histidine imidazole group on the active center of the enzyme to inactivate the enzyme B:is a competitive inhibitor of enzymes C:can be bind to the hydroxyl group of serine on the active center of the enzyme to inactivate the enzyme D:Can inhibit cholinesterase activity E:It can be bind to the thiol group of cysteine on the active center of the enzyme to inactivate the enzyme
答案:can be bind to the hydroxyl group of serine on the active center of the enzyme to inactivate the enzyme; Can inhibit cholinesterase activity
17.Trypsin can be activated（ ）
A:Trypsinogen B:chymotrypsinogen C:elastase D:Carboxypeptidase E:pepsinogen
答案:pepsin
18.Habitus that competitively inhibit the following enzymatic reactions are（ ）
A:Inhibition of cytochrome oxidase by CO B:Inhibition of succinate dehydrogenase by malic acid C:Organophosphorus pesticides inhibit acetylcholine D:Inhibition of dehydrogenate reductase by methotrexate E:5-fluorouracil inhibits thymidine synthase after in vivo changes
答案:Inhibition of succinate dehydrogenase by malic acid###5-fluorouracil inhibits thymidine synthase after in vivo changes###Inhibition of dehydrogenate reductase by methotrexate
19.The main way to get blood sugar is（ ）
A:Synthetic protein B:Conversion to other sugar and non-sugar substances C:Synthetic liver glycogen D:Decomposition of energy in tissue cells E:Synthetic muscle glycogen
答案:Decomposition of energy in tissue cells; Synthetic liver glycogen; Conversion to other sugar and non-sugar substances; Synthetic muscle glycogen