Question

19. You clone your favorite E. coli gene including the promoter region, the open reading frame, and some flanking DNA. You determine the DNA sequence of the entire region and map the start site of transcription. You note the following sequence near the end o your gene. What is the likely function of this sequence? ...CCCAGCCCGCCTAATGAGCGGGCTTTTTTTTTTGAAGGTATAT... A. A polyadenylation signal B. A Rut site C. The ribosome binding site for the next open reading frame in the operon D. The origin of replication E. An intrinsic terminator 20. Only Pol II transcripts are capped in eukaryotic cells. Why? A. Only Pol II transcripts leave the nucleus and capping takes place in the cytoplasm. B. Rho terminates any Pol I transcripts that happen to become capped. C. Only Pol Il transcripts are translated and the initiation factors are required to initiate capping.. D. The capping machinery assembles on the phosphorylated Pol Il tail. E. The 5' cap is removed from Pol I transcripts in the nucleolus. 21. Immediately after the action of EF-G, where in the ribosome is the tRNA that is bound to the partially synthesized protein? A. The E site (B. The P site C. The A site D. The Factor Binding Center E. The second "sieve"

can you guys please give me the correct answers and explain why?

Answer 1

19. A rut site - it is the sequence get recognised by rho protein and translation termination takes place . A polyadenylation signal has a different sequence .

20. D. The capping machinery assembles on the Phosphorylated pol II tail . Pol II has a C-terminal domain (CTD) that gets Phosphorylated during transcription and these Phosphorylated sites recruit capping machinery .

21. P site . Ribosomes has 3 sites E , P and A site at A site aminoacyl-tRNA binds then get transferred to P site where peptide bond formation takes place by between the partially synthesized protein and amino acid on tRNA then it moves to exit site (E site ) .