-生物化學(xué)-考研課件-ch11-核苷酸和核酸-nucleic-acids

1、BiochemistryFor Specialty of Biotechnology or Bioengineering at CSUMr. XIA JinlanChapter 11 Nucleotides and Nucleic acids 核苷酸和核酸Information transfer in a cell細(xì)胞中信息的轉(zhuǎn)化The bases, nucleoside and Nucleotide 堿基、核苷、核苷酸 Basic Structure of nucleic acids 核酸結(jié)構(gòu)Classes of nucleic acids 核酸的類型Hydrolyses of nuclei

2、c acids 核酸的水解Information transfer in a cell細(xì)胞中信息的轉(zhuǎn)化DNA is transforming material （DNA 是轉(zhuǎn)化物質(zhì)）Information flow and Central dogma信息流與中心法則DNA is transforming material （DNA 是轉(zhuǎn)化物質(zhì)）Griffths transforming experiments (1928) showed some materials inside the S strain had transferred to Live R strain 證明細(xì)胞內(nèi)物質(zhì)能在細(xì)胞

3、間轉(zhuǎn)化O T Avery testified the transforming substance was DNA (1944) 證明轉(zhuǎn)化物質(zhì)是DNA A Hershey and M Chase further testified transforming substance was DNA by infection of bacteria with T2 (1952) 進(jìn)一步通過(guò)噬菌體T2 對(duì)細(xì)菌感染的試驗(yàn)證明轉(zhuǎn)化物質(zhì)是DNAQuestion: Please point out the biomoleculesthat are related to the information flow.

4、請(qǐng)指出與信息流相關(guān)的生物分子Informationflow信息流mRNAProteinTranscription轉(zhuǎn)錄Reverse transcription反轉(zhuǎn)錄Translation翻譯Gene expression基因表達(dá)Central dogma 中心法則DNAThe bases, nucleoside and Nucleotide （堿基、核苷、核苷酸）Nucleoside=base-sugarThe two types of common basesThe two types of common sugarsNucleotide = Nucleoside-phosphateStru

5、cture of a representative nucleotide 代表性核苷酸結(jié)構(gòu)Names of common bases, nucleosides and nucleotides 常見堿基，核苷和核苷酸名稱High energy Phosophoester bonds 高能磷酯鍵Other important forms of nucleotides其它重要核苷酸類型Two types of bases in nucleic acidsPyrimidine 嘧啶Purine嘌呤Uracil尿嘧啶Thymine胸腺嘧啶Cytosine胞嘧啶Guanine鳥嘌呤Adenine腺嘌呤(o

6、nly inRNA)(only inDNA)In both DNA and RNATwo types of sugars in nucleic acidsD-RiboseD-2-Deoxyribose(only in RNA)(only in DNA)Structure of a representative nucleotide代表性核苷酸結(jié)構(gòu)e.g., Adenine 腺嘌呤, Adenosine 腺苷, Adenosine phosphate 腺苷酸Base: adenineNucleoside: adenosineNucleotideAdenosine 5-monophosphateA

7、denosine 5-diphosphateAdenosine 5-triphosphateNames of common bases, nucleosides and nucleotides 常見堿基，核苷和核苷酸Base 堿基Nucleoside 核苷Nucleotide核苷酸basePurines Adenine, AGuanine, Gbase-(deoxy)ribose(deoxy)Adenosine(deoxy)Guanosinebase-(deoxy)ribose-phosphate(d)ATP, (d)ADP, (d)AMP(d)GTP, (d)GDP, (d)GMPPyrim

8、idinesThymine, TCytosine, C(deoxy)Thymidine(deoxy)Cytidine(d)TTP, (d)TDP, (d)TMP(d)CTP, (d)CDP, (d)CMPADP (adenosine 5-diphosphate)ATP (adenosine 5-triphosphate)The high energy phosophoester bondsExamples Other important forms of nucleotidesBasic Structure of nucleic acids 核酸基本結(jié)構(gòu)Nucleotides bind tog

9、ether by 3 5-phosphodiester bonds5 end: phosphate3 end: hydroxyl groupNucleic acids or polynucleotides are written as base sequences 核酸或多核苷酸的書寫方式是堿基序列Nucleic acids or polynucleotides are also expressed by schematical mode 核酸也可以圖解方式表示Structure of nucleic acids 核酸結(jié)構(gòu)Binding together by 3 5-phosphodiest

10、er bonds5 end: phosphate3 end: hydroxyl groupTake DNA as anexampleComparison of chain structure between RNA and DNAWritten forms of Nucleic acids or polynucleotides 核酸或多核苷酸的書寫方式Simply list the single capital letters of basese.g., GACTGUAWith p to indicate the phosphodiester bridge用磷（酸根）指出磷二酯鍵GpApCpT

11、pGpUpAp (3-OH end)pGpApCpTpGpUpA (5-OH end)Schematical expressing mode of nucleic acids 核酸圖解表示方式Or simplyClasses or nucleic acids 核酸的類型DNARNAmRNA (messenger )tRNA (transfer )rRNA (ribosome )snRNA (small nuclear , only in Eucaryotic cells)Problem for self-study: Where are the locations of the differe

12、nt classes of nucleic acids in a procaryotic or eucaryotic cell, respectively, and what are their functions?Hydrolysis of nucleic acids 核酸水解Hydrolysis by acid or base 酸或堿性水解Randomly 隨機(jī)（水解）DNA is acidic labile, e.g., be hydrolysed the purine glycosidic bonds by 1mM HCl （DNA易于被稀酸水解）RNA is alkali labil

13、e, e.g., hydrolyzed by dilute NaOH（RNA易于被稀堿水解）Enzymatic hydrolysisSpecifically 特異性地水解Nuclease specificity核酶特異性RNases, DNases or nucleases (both for DNA and RNA)Exonucleases 外切核酸（水解）酶Endonucleases 內(nèi)切核酸（水解）酶Restriction enzymes 限制性（水解）酶 (see table 11.4, p349)2-OH in ribose of RNA is susceptible to nucleo- philic attack on 3-phosp