6. How is all RNA made? Describe the process of translation in terms of the three types of RNA discussed in this unit.

1. Which types of RNA are transcribed by each RNA polymerase enzyme in eukaryotic cells?

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.

17. How would you computationally predict the thermodynamic stability of a long, extended RNA helix? Please explain in 1 sentence how structural "favorability" can be predicted

6. In RNA, why can uracil be used in place of thymine? * The structural difference between thymine and uracil does not affect hydrogen bonding to adenine Thymine and uracil are actually identical bases, but they're named differently because one is in DNA and the other is in RNA Uracil forms two hydrogen bonds with adenine, but using different atoms than thymine O Uracil can interact with adenine via three hydrogen bonds 7. At least how many different types of RNA are there in eukaryotic cells? * 1: just messenger RNA 2: messenger RNA and ribosomal RNA 3: messenger RNA, ribosomal RNA, and transfer RNA 6: the three listed above in C, plus microRNA, small interfering RNA, and small nuclear RNA 1