5' caps and 3' poly(A) tails of eukaryotic mRNAs _____.
protect mRNA from degradation and enhance translation
How are RNA hairpin turns related to termination?
The turns are formed from complementary base pairing and cause separation of the RNA transcript and RNA polymerase.
How does the bacterial ribosome recognize where to start translation?
The small ribosomal subunit binds to a sequence in the mRNA just upstream of the start codon.
Of the three modes of gene regulation (Transcriptional control, Translational control, Post-translational control), which is the fastest in response time?
Post-translational control..... bc it involves modification of an already synthesized protein
What is the pattern of expression of β-galactosidase in lacI- cells and why?
constitutive expression, because there is no repressor
Which of the following is part of a DNA molecule?
- the holoenzyme
- initiation factors
Which of the following statements is correct?
- During elongation, the RNA strand is extended in a 5' to 3' direction.
- Sigma factor is needed to recognize the transcriptional termination signal.
- The bacterial RNA holozyme is used during the elongation phase of transcription.
- The bacterial promoter lies just downstream of the start site of transcription.
During elongation, the RNA strand is extended in a 5' to 3' direction.