2009 분자생물학2 Quiz 2

학번                             성명

1	다음 내용에서 These proteins이 무엇인지 구체적인 명칭을 쓰시오.

At the completion of a splice. the spliceosome directs a set of proteins to bind to the mRNA near the position formerly occupied by the intron. These proteins mark the site of a successful splicing event and, as we shall see later in this chapter, influence the subsequent fate of the mRNA.

2	일반적으로 인트론은 GU로 시작하고 AG로 끝난다. 그러나 소수의 인트론은 AU로 시작하여 AC 로 끝난다. 이러한 인트론의 splicing에 관여하는 독특한 snRNA에는 어떤 것이 있는지 한 가지만 쓰시오.

3	일부 원생동물에서는 서로 다른 RNA의 exon을 연결하는 splicing방법을 사용하고 있다. 이러한 형태의 splicing을 무엇이라고 하는가?

4	다음 문장에서 some of these proteins에 해당하는 것이 무엇인지 쓰시오

Some of these proteins(there are approximately 30 of them in humans) unwind the hairpin helices from the RNA so that splicing and other signals on the RNA can be read more easily. Others preferentially package the RNA contained in the very long intron sequences typically found in genes of complex organisms. They may therefore play an important role in distinguishing mature mRNA from the debris Ieft over from RNA processing.

다음 (     )를 채우시오

5	In eucmyotic cells, the process of transcription is much more complex, and there are three RNA polymerases, polymerase I, II, and III -that are related evolutionarily to one another and to the  bacterial polymerase. (                  )synthesizes eucaryotic mRNA. This enzyme requires a series of additional proteins, the general transcription factors, to initiate transcription on a purified DNA template, and still more proteins (including chromatin-remodeling complexes and histone-modifyingenzymes) to initiate transcription on its chromatin templates inside the cell. For some genes. RNA is the final product. In eucaryotes. these genes are usually transcribed by either

(                ) or (              ).

6	Not long after thefirst gene regulatory proteins were discovered  in bacteria, genetic analyses in the fruit fly Drosophila  led to the characterization of an important class of genes, the

(                             ), that plays critical part in orchestrating fly development.

7	To initiate the translation , a small ribosomal subunit binds to the mRNA molecule at a start codon(AUG) that is recognized by a unique initiator tRNA molecule. A large ribosomal subunit bintls to complete the ribosome and begin protein synthesis. During this phase. aminoacyl-tRNAs—each bearing a specific amino acid-bind  sequentially to the appropriate codons in mRNA through complementary base pairing between tRNA anticodons and mRNA codons. Each amino acid is added! to the C·termiual end  of  the growing polypeptide in four sequential steps: aminoacyl-tRNA bnding, followed by (                       ). followed by two ribosome translocation steps. Elongation  factors use (          ) hydrolysis to drive these reactions forward  and to improve the accuracy of amino acid selection while mRNA molecule progresses codon by codon through the ribosome in the 5' -to-3' direction until it reaches one of three stop codons.