exam_5a - Biol 638, Exam-5 (Code-1) Biology 638...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Biol 638, Exam-5 (Code-1) 1 Biology 638 – Biochemistry II Exam-5 (May 3, 2010) In questions 1 - 23 , one statement is not true. Select that statement. (Note: Read every statement very carefully before selecting your answer) 1 . Following are some descriptions of transcription factors. a. PIC interacts with transcription factors that are on upstream enhancers. b. Leucine zippers is a structural motif seen in DNA binding proteins. c. Some of steroid receptors are inducible transcription factors which bind usually on a downstream enhancer. d. General transcription factors are components of PIC. e. None of the above. 2 . Following are some descriptions of promoters and enhancers. a. The GC box sequences are seen in upstream of antisense strand in some of eukaryotes. b. The selectively transcribed genes of eukaryotes have a TA-rich sequence in the promoter section. c. Enhancers are binding sites of transcription factors in DNA. d. The Pribnow boxes are found in prokaryotic DNAs and are similar to the TATA boxes. e. None of the above. 3 . Following are some descriptions of transcription processes. a. The initiation sites on the antisense strands are most likely C or T. b. The major function of sigma-70 in prokaryotic RNA polymerase is to recognize the initiation site. c. Rho factor binds after a GC rich palindromic sequence and terminates some RNA synthesis. d. RNA polymerization requires unwinding and winding DNA in front and behind the transcription bubble, respectively. e. None of the above. 4 . Following are some descriptions of the posttranscriptional processing of RNA synthesis. a. Cap-1 is the predominant cap mRNA, in which the 2’-OH of the 5’-end of residue is methylated. b. Poly(A) binding protein forms a complex with Poly(A) seen at the 3’-end of eukaryotic mRNAs. This complex formation protects mRNA from degradation by nucleases. c. In general, eukaryotic mRNAs are much longer than the corresponding prokaryotic mRNAs. d. 7-Methyladenosine is attached to the 5’-end of eukaryotic mRNA, which is recognized by 16S rRNA. e. None of the above.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Biol 638, Exam-5 (Code-1) 2 5 . Following are some descriptions of eukaryotic pre-mRNAs. a. Primary transcripts of mRNAs are much longer than mature mRNAs. b. mRNAs can be isolated using a poly(A)-resin column. c. In the self splicing reaction, 2’-OH of adenine residue in the intron attacks phosphate at 5’-end of the same intron to break the P-O5’ bond. d. Introns have the AG sequence at the 3'-end and the GU sequence at the 5'-end and have consensus sequences, CURAY (R = purine, Y = pyrimidine) in the middle. e. None of the above.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 5

exam_5a - Biol 638, Exam-5 (Code-1) Biology 638...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online