10. Transcription
RNA Modification and Processing
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Practice this topic
- Multiple Choice
Which of the following is NOT a method of mRNA modification?
- Multiple Choice
The spliceosome is made up of which of the following components?
- Multiple Choice
Which of the following is not a sequence that the spliceosome recognizes?
- Multiple Choice
After transcription the RNA sequence cannot be changed or modified before translation.
- Open Question
Answer these questions concerning promoters. What role do promoters play in transcription?
- Open Question
A short RNA molecule was isolated that demonstrated a hyperchromic shift (see Chapter 10), indicating secondary structure. Its sequence was determined to be
5'-AGGCGCCGACUCUACU-3'
Propose a two-dimensional model for this molecule. - Open Question
Present an overview of various forms of posttranscriptional RNA processing in eukaryotes. For each, provide an example.
- Open Question
One form of posttranscriptional modification of most eukaryotic pre-mRNAs is the addition of a poly-A sequence at the 3' end. The absence of a poly-A sequence leads to rapid degradation of the transcript. Poly-A sequences of various lengths are also added to many bacterial RNA transcripts where, instead of promoting stability, they enhance degradation. In both cases, RNA secondary structures, stabilizing proteins, or degrading enzymes interact with poly-A sequences. Considering the activities of RNAs, what might be general functions of 3'-polyadenylation?