Week 6

Which of the following is true of RNA synthesis (transcription)?

• RNA synthesis is always in the 3' - 5' direction
• It is carried out by RNA polymerase
• In transcription, U is inserted opposite T
• New nucleotides are added on to the 5' OH of the ribose sugar

If a coding sequence reads 5’ ATGTCG 3’, what will the RNA produced be?

• 5’ AUGUCG 3’
• 5’ GCUGUA 3’
• 5’ UACAGC 3’
• 5’ CGACAU 3’

Which of the following is true regarding transcription in prokaryotes?

• Prokaryotes have 3 types of RNA polymerase
• Transcription begins with RNA polymerase binding to the enhancer
• Rho-dependent termination involves the RUT sequence
• Intrinsic termination occurs at AT-rich areas followed by string of U’s

Which of the following is false? The genetic code:

• Uses nucleotide triplets called codons
• Is overlapping with 3 reading frames
• Is degenerate
• Is unambiguous

Which of the following is true about codons?

• There are 61 codons
• UAG, UAA and UGA are stop codons
• AUG codes for formal-methionine only
• One codon can encode many amino acids

Which is not involved in translation?

• Ribosome
• tRNA
• Aminoacyl-mRNA synthetase
• mRNA

What does the RNA polymerase holoenzyme do?

• It helps activate RNA polymerase
• It helps terminate RNA synthesis
• It locates the promoter on the DNA
• It is the catalytic centre of RNA polymerase

Which of the following are features of the wobble hypothesis?

• A tRNA can recognise only one codon
• tRNAs can recognise codons that specify different amino acids if non-polar
• The “wobble” only occurs in the first base of the codon
• The “wobble” only occurs in the third base of the codon

Which of the following is true?

• Many molecules of RNA polymerase simultaneously transcribe one gene
• Promoters of E.coli genes contain one strongly conserved region
• The energy for RNA synthesis comes from the hydrolysis of ATP
• Both the template and coding strands can be transcribed at any one time