生物新人教版必修《基因指導蛋白質的合成》課件ppt

1、基因指導蛋白質的合成1. mRNA(信使信使RNA） Messenger RNAs-are the nucleic acids that record information from DNA in the cell nucleus and carry it to the ribosomes and are known as messenger RNAs (mRNA). （功能：作為編碼蛋白質中氨基酸的模板功能：作為編碼蛋白質中氨基酸的模板）2.rRNA (核糖體核糖體RNA）Ribosomal RNAs-exist outside the nucleus in the cytoplasm o

2、f a cell in structures called ribosomes Ribosomes are small, granular structures where protein synthesis takes place. Each ribosome is a complex consisting of about 60% ribosomal RNA (rRNA) and 40% protein. (功能：功能：核糖體的核糖體的 組成結構的一部分）組成結構的一部分）3. tRNA (轉運轉運RNA）Transfer RNAs-The function of transfer RNA

3、s (tRNA) is to deliver amino acids one by one to protein chains growing at ribosomes. （功能：功能：轉運氨基酸）轉運氨基酸）Translation is the process by which the genetic messages carried by mRNA are decoded and used to build proteins in the cytoplasm1.Station cytoplasm2.Templet mRNA3.Material amino acids4.Products p

4、roteinsA set of three nucleotide bases on an mRNA molecule is called a codon.(翻譯是在細胞質中進行的。它是指以信使RNA為模板，合成具有一定氨基酸順序的蛋白質的過程。）(場所；細胞質)( 模板：信使RNA)(原料：氨基酸)( 產物：蛋白質)(信使RNA上決定一個氨基酸的三個相鄰的堿基叫一個密碼子）UCAUG A UUAmRNACODONCODONCODON 1. Each codon specifies a single amino acid .For example,CGC encodes arg.(一個密碼子編碼

5、一個氨基酸，例如CGC編碼精氨酸） 2.大多數氨基酸有多個密碼子，例如，GUU，GUA都編碼纈氨酸3.AUG（編碼甲硫氨酸）為起始密碼子，翻譯從此密碼子開始，少數起始密碼子為GUG4.UAA,UAG,UGA（終止密碼子，不編碼任何氨基酸），翻譯到次終止1.Initiation AUG,GUG（起始密碼子）2.Stop UAA,UAG,UGA（終止密碼子）3.One codon decides one amino acid一個密碼子決定一個氨基酸4. one amino acid may have many codons一個氨基酸可有多個密碼子UCAUG A UUAA U CMetUU AT P

6、rotein synthesis occurs in three stages: Initiation, Elongation and Termination.(蛋白質的合成包括三個步驟：起始，延長，終止) 1. Initiation(起始) mRNA attaches to the ribosome.(mRNA與核糖體結合）與核糖體結合）A set of three nucleotide bases on a tRNA molecule is called an anticodon(反密碼）A A ULDNA bases=RNA base =3 amino acidQuestions1.Fo

7、r the DNA strand 5-TACGATCATAT-3 the correct complementary DNA strand is: A.3-TACGATCATAT-5 B.3-ATGCTAGTATA-5C. 3-AUGCUAGUAUA-5 D. 3-GCATATACGCG-5E. 3-TATACTAGCAT-52.In the Meselson-Stahl DNA replication experiment, if the cells were first grown for many generations in N-15 containing media, and the

8、n switched to N-14 containing media, what percent of the DNA had 1 light strand and 1 heavy strand after 2 generations of growth in N-14 growth media? A.0 B.25 C.50 D.75 E.100BC3.Three types of RNA involved in comprising the structural and functional core for protein synthesis, serving as a template

9、(模板) for translation, and transporting amino acid, respectively, are: A A mRNA, tRNA, rRNA B B rRNA, tRNA, mRNA C C tRNA, mRNA, rRNA D D tRNA, rRNA, mRNA E rRNA, mRNA ,tRNA4.A messenger RNA is 336 nucleic acids, including the initiator and termination codons. The number of amino acids in the protein translated from this mRNA is: A A 999 B B 630 C C 330 D D 111 E E 110ED 5.With what mRNA codo