2. What is the role of the Promotor Region and the highly characterized promoter sequence, the TATA Box, in the process of DNA transcription? What nucleotides does the TATA box mainly consist of? ✓✓

2. You perform a series of experiments on the synthesis of the pituitary hormone prolactin, which is a single polypeptide chain 199 amino acids long. In the first experiment, the MRNA coding for prolactin is translated in a cell-free protein synthesizing system containing ribosomes, amino acids, tRNAs, aminoacyl-TRNA synthetases, ATP, GTP, and the appropriate initiation, elongation, and termination factors. Under these conditions, a polypeptide chain 227 amino acids long is synthesized. In a second experiment, the MRNA is translated in the same cel1-free system to which you have added SRP. In this case, translation stops after a peptide about 70 amino acids long has been produced. In a third experiment, you use the same cell-free translation system to which you have added both SRP and endoplasmic reticulum vesicles, and you find that that the prolactin MRNA now produces a polypeptide that is 199 amino acids long. A) Explain these results.

6.  explain what coupled transcription-translation is, and why it occurs in prokaryotes but not eukaryotes

8. Which of the following gene mutations is most likely to affect correct protein production? The boxes are the exons and the lines are the introns in the gene a. b. C. d. Site 1 Site 2 Explain WHY. 1+ Site 3 Site 4 a two base-pair deletion at Site 1 that removes two "G-C" nucleotide pairs from the gene sequence a single base-pair substitution at Site 2 that changes a tyrosine-encoding amino acid (TAC) to a stop codon (TAA) a single base-pair substitution at Site 3 that changes one alanine-encoding codon (GCC) to another (GCA) a single base-pair insertion at Site 4 that shifts the reading frame for subsequent codons

1. What happens during transcription? Possible sentence frame: Transcription is the process in which the information from converted into This happens by is

8. ----ATTATA-- -ТААТАТ-- Fill in the polarity of the strands? Which strand is the coding strand? Which strand is the template strand? What is the direction of transcription? 9. You have a nucleic acid with the following percentages of bases 1. A=35% G=32% T=8% C=25% II. A=20% G=32% T=18% C=30% III. A=23% G=14% U=42% C=21% For the 3 nucleic acids above, determine whether it is single stranded or double stranded DNA or RNA 10. An RNA molecule has the following percentages of bases A=16% G=27% U=37% C=20% What would be the percentage of bases in the template strand of the DNA that contains the gene for this RNA?

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