Question

want to double check!

25. Th e DNA sequences encoding the initiation whese parated bcoding the initiation and termination codons of a certain protein amino acids in length. there of the protei nucleotides on a certain organism's chromosome; however ssuming that there has been no post-translational processing elined from this gene is translated, the protein product is only 250 A. The RNA was synthesized in a bacterial cell n, what can you conclude from these observations? The RNA was synthesized in a eukaryotic cell gene product in question is an integral membrane protein D. the cell's ribosomes are not functioning correctly E. noth ing can be concluded from the above information During the elongation phase of protein synthesis, an uncharged tRNA can NEVER occupy site of the ribosome A. A D. all of the above E. none of the above 27. What do codons and anticodons most have in common? A. They are part of tRNA. B. They are sequences of DNA three nucleotides long C. They are identical RNA sequences hey are complementary RNA sequences They both interact with tmRNA in order to function. 28/A microbial genome encodes 5000 proteins that have an average length of 200 amino If the organism's complete proteome is encoded by 10% of its genome, what is the length of that genome? A. 2 x 106 base pairs. geniu-500pr 00 AA oC B. 8 x 106 base pairs. C. 3 x 10 base pairs. D. 1 x 108 base pairs. l E. 5 x 108 base pairs scripts is often initiated before transcription 9. In Bacteria, translation of nascent RNA tran is terminated. When this occurs: A. RNA is transcribed 5'→3, and amino acids are added to t he amino terminus of the growing polypeptide as the ribosome moves 3' → 5' along the mRNA RNA istranscribed 5→3, and amino acids are added to the car growing polypeptide as the ribosome moves 5, boxy terminus of the B. 3 amino acids are added to the amino terminus of the RNA is transcribed 3-95, and growing polypeptide as the ribosome moves 3→ 5 along the mRNA mino acids are added to the carboxy terminus of the RNA is transcribed 3'→5' and a growing polypeptide as the ribosome moves 5→ 3, along the None of the above mRNA E. ner membrane is mis- localized in the cytoplasm. All other proteins show normal localizat probably has the following defect: A. The signal recognition particle is missing. B. The sigma factor that helps transcribe this protein is missing. normal localization. This strain 30. In a mutant E. coli strain, a protein that normally resides in the in

Answer 1

26.

Incorrect: methionine carrying tRNA which is the first tRNA land in the middle slot present in the ribosome. The middle slot in the ribosome is the P site. The fresh charged tRNA land on the A site. To form the peptide chain, methionine transfer from the first tRNA to the amino acid carrying second tRNA in the A site.

Hence, the options (B), (C), (D) and (E) are incorrect.

Correct: uncharged tRNA is one that do not contain the amino acid. At the termination step when all the amino acid transferred to form the polypeptide chain, the uncharged tRNA comes out through the P site.

Hence, the correct option is (A).

27.

Incorrect: tRNA contain only the anticodons (triplet sequence) for the codons present on the mRNA. Codons and anticodons are made of three nucleotides but not the sequence of DNA. Also these are not the identical RNA sequences as these are not present on the same type of RNA.

Hence, the options (A), (B), (C) and (E) are incorrect.

Correct: the common thing exist between the codons and anticodons is that, they are the complementary RNA sequences. For every codon present on the mRNA has complementary anticodon present on the tRNA.

Hence, the correct option is (D).