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CHAPTER 7 FROM DNA TO PROTEIN: HOW CELLS READ THE GENOME © 2004 Garland Science P!li #in$ Fr%& DNA '% RNA 7-1 RNA in cells differs from DNA in that (a) it contains the base uracil, which pairs with cytosine. (b) it is single-stranded and cannot form base pairs. (c) it is single-stranded and can fold up into a variety of structures. (d) the nucleotides are lined together in a different way. (e) the sugar ribose contains fewer o!ygen atoms than does deo!yribose. 7-2 ranscription is similar to DN
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  C HAPTER  7 FROM DNA TO PROTEIN:HOW CELLS READ THE GENOME ©  2004 Garland Science P!li #in$ Fr%& DNA '% RNA 7-1 RNA in cells differs from DNA in that(a)it contains the base uracil, which pairs with cytosine.(b)it is single-stranded and cannot form base pairs.(c)it is single-stranded and can fold up into a variety of structures.(d)the nucleotides are lined together in a different way.(e)the sugar ribose contains fewer o!ygen atoms than does deo!yribose. 7-2 ranscription is similar to DNA replication in that(a)it re#uires a molecule of DNA helicase to unwind the DNA.(b)it uses the same en$yme as that used to synthesi$e RNA primers during DNA replication.(c)the newly synthesi$ed RNA remains paired to the template DNA.(d)nucleotide polymeri$ation occurs only in the % ′ -to-& ′  direction.(e)an RNA transcript is synthesi$ed discontinuously and the pieces then 'oined together. 7-3 or each of the following sentences, fill in the blans with the best word or phrase selected from the list below. Not all words or phrases will be used each word or phrase should be used only once.*n order for a cell+s genetic material to be utili$ed, the information is first copied from the DNA into the nucleotide se#uence of RNA in a process called . arious inds of RNAs are produced, each with different functions.  molecules code for  proteins,  molecules act as adaptors for protein synthesis,  molecules are integral components of theribosome, while  molecules are important for splicing of RNA transcripts.incorporationrRNAtransmembranemRNAsnRNAtRNA pRNAtranscription proteinstranslation (0)  7-4 atch the following structures with their names/igure 01-2 7-5 *magine that an RNA polymerase is transcribing a segment of DNA that contains the se#uence/ 5 ′ - AGTCTAGGCACTGA -3 ′ 3 ′ - TCAGATCCGTGACT -5 ′ A.*f the polymerase is transcribing from this segment of DNA from left to right, which strand (top or bottom) is the template34.5hat will be the se#uence of that RNA (be sure to label the % ′  and & ′  ends of your RNA molecule)3 7-6 he sigma subunit of bacterial RNA polymerase(a)contains the catalytic activity of the polymerase.(b)remains part of the polymerase throughout transcription.(c)recogni$es promoter sites in the DNA.(d)recogni$es transcription termination sites in the DNA. 7-7 5hich of the following might decrease the transcription of only one specific gene in a  bacterial cell3(a)A decrease in the amount of sigma factor (b)A decrease in the amount of RNA polymerase(c)A mutation that introduced a stop codon into the DNA preceding the coding se#uence of the gene(d)A mutation that introduced e!tensive se#uence changes into the DNA preceding the transcription start site of the gene(e)A mutation that moved the transcription termination signal of the gene farther away from the transcription start site (04  7-8 rom the list below, pic 6R77 reasons why the primase that is used to mae the RNA  primer for DNA replication would not be suitable for gene transcription3(a)8rimase initiates RNA synthesis on a single-stranded DNA template.(b)8rimase can initiate RNA synthesis without the need for a base-paired primer.(c)8rimase synthesi$es only RNAs of around % to 9: nucleotides in length.(d) he RNA synthesi$ed by primase remains base-paired to the DNA template.(e)8rimase uses nucleotide triphosphates. 7-9 *ndicate where the following processes tae place by adding numbered labeling lines to the schematic diagram of a eucaryotic cell in igure 01-;.igure 01-;<. ranscription9. ranslation&.RNA splicing2.8olyadenylation%.RNA capping 7-10 otal nucleic acids are e!tracted from a culture of yeast cells and are then mi!ed with resin beads to which the polynucleotide % ′ - -& ′  has  been covalently attached. After a short incubation, the beads are then e!tracted from the mi!ture. 5hen you analy$e the cellular nucleic acids that have stuc to the beads, which of the following will be most abundant3(a)DNA(b)tRNA(c)rRNA(d)mRNA(e)8rimary transcript RNA 7-11  Name three modifications that can be made to an RNA molecule in eucaryotic cells  before the RNA molecule becomes a mature mRNA. (0*  7-12 he length of a particular gene in human DNA, measured from the start site for transcription to the end of the protein-coding region, is <:,::: nucleotides, whereas the length of the mRNA produced from this gene is 2::: nucleotides. 5hat is the most lielyreason for this discrepancy3 7-13 A fragment of human DNA containing the gene for a protein hormone with its regulatory regions removed is introduced into bacteria although it is transcribed at a high level into RNA, no protein is made. 5hen this RNA is e!tracted from the bacteria, mi!ed with human mRNA encoding the same hormone, and then e!amined in the electron microscope, you see the following structure (igure 01-<&). =abel each of the statements  below as either >consistent? or >inconsistent? with your results and e!plain your reasoning.igure 01-<&A. he human DNA was inserted in the bacterial DNA ne!t to a bacterial promoter and in its normal orientation.4. he human DNA was inserted in the bacterial DNA ne!t to a bacterial promoter  but in an orientation opposite to normal.@. he human DNA contained an intron.D. he human DNA ac#uired a deletion while in the bacterium. 7-14 5hy is the old dogma >one geneone protein? not always true for eucaryotic genes3 7-15 *s this statement RB7 or A=C73 7!plain your answer.>Cince introns do not contain protein coding information, they do not have to be removed precisely (meaning, a nucleotide here and there should not matter) from the primary transcript during RNA splicing.? (0+

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