上海交大生物化学教材上册习题答案doc.docx

1、上海交大生物化学教材上册习题答案docChapter 21. (a) tropomyosin原肌球蛋白 70-kd 35-kd (two-stranded) 318 residues (mean residue mass 110) 477(axial distance of per residue in -helix is 1.5)(b)40 residues 36 (4 for hairpin turn) 18 (two-stranded) 63 (the rise per residue 3.5 in sheet) motif基序 mom基基t2. contrasting isomer截然

2、不同的异构体 dioxane二噁烷 in Leu methyl甲基 is attached to -C atom, while in Ile it to -C atom(比较靠近主链-碳原子,造成立体位阻,阻断-螺旋的形成)3. Ala Val; Ile Gly AlaIle. with activity (wild type) ValIle lose activity (mutant type) ValGly regain activity (double-mutant type)4. shuffle重新洗牌, disulfide-sulfhydryl exchange二硫键-巯基互换; P

3、DI蛋白二硫键异构酶, scrambled ribonuclease杂乱的核糖核酸酶 杂乱的核糖核酸酶在PDI作用下由无序变成有序,而胰岛素则由有序变成无序,说明胰岛素结构并非热力学最稳定的形式;因为胰岛素是由(比它多33个残基的)胰岛素原形成的,后者才是热力学最稳定的形式.5.stretching a target使目标(蛋白底物)伸展; protease蛋白水解酶6. Gly has the smallest side chain of AA: tight turns and approaching one another closely7.guanidinium group胍基 of A

4、rg (positive): Glu, Asp, and the terminal carbonyl group (negative)8.keratin角蛋白 烫发: 加入巯基化合物(作为还原剂)和适当的温度使原来(发型中)的二硫键打断,卷曲头发(至所需型态)并加入氧化剂,使之形成新的二硫键并稳定.Chapter 31.(a)phenyl isothiocyanate (PITC) 异硫氰酸苯酯 (b)Dansyl chloride丹黄酰氯(or dabsyl chloride) (c)Urea尿素; -mercaptoethanol -巯基乙醇 (d)chymotrypsin糜蛋白酶 (N)

5、R-X(C) R: Phe Trp, Tyr (e)CNBr (N)Met-X(C) (f)Trypsin (N)R-X(C) R: Arg or Lys2. K=H+A/HA pH=pK +log A/HA3.anhydrous hydrazine无水肼: 处理多肽(蛋白质)发生裂解,羧基末端的氨基酸释放成游离氨基酸,可被鉴定.所有其他氨基酸残基变成酰肼衍生物. 4. ethyleneimine乙烯亚胺 + Cys S-aminoethyl氨乙基 derivatives (S-氨乙烯半胱氨酸) 与Lys类似 Cys*-X5. incident入射, transmitted透射, extinc

6、tion coefficient (molar absorption coefficient)消光系数; I = I0 10lcA (log I0/I) =lc 1mg/ml 5.62 x 105 M (MW= 17.8 kd) A = 15000 x 5.62 x 105 x 1= 0.84 = log10(I0/I) I0/I=6.96 即14.4%的入射光被透射6. tropomyosin原肌球蛋白rod shaped7.s m/f f = 6r m r3 s m2/38. y = kx + b log (MW) = k (RM) + b y log (MW) MW:molecular

7、weight XRM: relative mobility log 92000 = 0.41 k + b log 30000 = 0.80 k + b k= 1.26 b= 5.465So, the apparent mass of a protein having a mobility of 0.62 is 50 kdChapter 41. 5 GATCAA 33 CTAGTT 55TTGATC3(书写自左向右53)3. 17m15m = 2m = 20000A3.4A = 5800 base pairs4A(15N) B(14N) Conservative replication: AA

8、AA+BB (F1) AA+BB+ BB+ BB(F2)Semiconservative replication: AA AB+ AB (F1) AB+ AB +BB+ BB (F2)6. competence感受态 Bacillus subtilis枯草芽胞杆菌 possible reason: 1.not able to take up DNA 2.having deoxiribonuclease脱氧核糖核酸酶 3.not able to integrate fragments of DNA into their genome7. propitious有利的; T2 is used by

9、Hershey and Chase (P78) to separate itself into genetic (DNA) and nongenetic (protein) parts. M13 is not. (它的蛋白外壳将嵌入宿主的内膜,离心后将随细胞沉淀)8. （a）tritiated thymine (or thymidine)氚标记的胸腺嘧啶（胸苷）T* dTTP* DNA* (b) dNs-P*PP9. 5_3-OH 3-OH_510. reverse transcriptase逆转录酶 polyriboadenylate聚腺苷酸 primer引物 deoxythymudylat

10、e oligonucleotide寡聚脱氧胸苷酸 template: poly(rA) primer oligo dT synthetic material dTTP3 AAAAAAAAAAA5 TTT(OH) 11.RNADNA-RNA hybrid DNA transcript double-helical viral DNA () ( ) () ()(both by reverse transcriptase) ribonuclease核糖核酸酶； polymerase聚合酶; 逆转录酶兼具聚合酶和核糖核酸酶的功能12Turnip 芜菁 Virus treated with phenol

11、苯酚 (to remove protein) NA (divide into two samples) 1. treated with ribonuclease核糖核酸酶 2. treated with deoxyribonuclease脱氧核糖核酸酶13G-C G-U (by deamination脱氨) G-C A- U (after one round of replication) G-C G-C A- U A- T (after two round of replication)14. hydrogen cyanide氰化氢(HCN) pentamer五聚体 adenine腺嘌呤(H

12、5C5N5)15. (a) AA AC AG AT 24CA CC CG CT GA GC GG GT TA TC TG TTCHAPTER 51. (a) dATP, dCTP, dGTP, dTTP (for DNA); ATP, CTP, GTP, UTP (for RNA)2. (a) 3ATTGCCATGCTA-5 5-UAACGGUACGAU-3 (b) 5-UUGCCUAGUGAUUGGAUG-3 N-LeuProSerAspTrpMet-C 5-UUACUUACUUACUUACUUACUUAC-3 Poly(UUAC) N-LeuLeuThrTyr-LeuLeuThrTyr-C

13、 Poly(Leu-Leu-Thr-Tyr) 5-UUACUUACUUACUUACUUACUUAC-3 N- Tyr- Leu- Leu- Thr. Poly(Tyr-Leu-Leu-Thr) 5-UUACUUACUUACUUACUUA -3 N- Thr - Tyr- Leu Leu. Poly(Thr-Tyr-Leu-Leu)4. ccordycepin蛹虫草菌素 3-deoxyadenosine脱氧腺苷 It terminates RNA synthesis because it lacks a 3-OH group. 5. poly(G)聚鸟苷酸forms a triple-stran

14、ded structure三股螺旋结构, therefore it cant serve as a template for protein synthesis. Poly(A), poly(C) and poly(U) can do as single-stranded RNA.6. 5TACTACTAC3 3 ATGATGATG ATGATGATG5 DNA聚合酶，连接酶5 TACTACTACTACTACTACTAC3 3 ATGATGATGATGATGATGATG5RNA polymerase +only UTP, ATP, CTPonly poly(UAC) 3ATGATGATGATG

15、ATGATG5 5UACUACUACUACUAC3RNA polymerase +only UTP, ATP, GTPonly poly(GUA) 3CATCATCATCATCATCAT5 5 GUAGUAGUAGUAGUA37. Lys: (AAA or AAG); (a) Asp: GAU or GAC impossible(b)Arg: AGA or AGG; Asn: AAU or AAC; Gln: CAA or CAGand Glu, Ile, Met, Thr palatable合口味8. triple entendre三关语5-AAAUGAGGA-3 3 different-polypeptide products:(a). 5-