The enzyme complex associated with DNA in the figure is ________.
They bind the sigma subunit that is associated with RNA polymerase.
) David Pribnow studied the base sequences of promoters in bacteria and bacterial viruses. He found two conserved regions in these promoters (the -10 box and the -35 box). What is the function of these two regions of the promoter?
3, 1, 2, 5, 4
Put the following events of transcription in chronological order. 1. Sigma binds to the promoter region. 2. The double helix of DNA is unwound, breaking hydrogen bonds between complementary strands. 3. Sigma binds to RNA polymerase. 4. Sigma is released. 5. Transcription begins.
The turns are formed from complementary base pairing and cause separation of the RNA transcript and RNA polymerase. The hairpin turn prevents more nucleoside triphosphates from entering the active site of the enzymes, effectively shutting off
How are RNA hairpin turns related to termination?
the phosphate bonds in the nucleotide triphosphates that serve as substrates
Which molecule or reaction supplies the energy for polymerization of nucleotides in the process of transcription?
larger than; the same size as
A primary transcript in the nucleus of a eukaryotic cell is ________ the functional mRNA, while a primary transcript in a prokaryotic cell is ________ the functional mRNA.
the -10 box
The TATA box of the eukaryotic promoter is analogous to which structure of the prokaryotic promoter?
Alpha-amanitin efficiently interferes with the action of RNA polymerase II, but not RNA polymerase I or III.
Death cap mushrooms produce a substance called -amanitin. Alpha-amanitin efficiently blocks synthesis of mRNA, but not of tRNA or rRNA in eukaryotic organisms. How is that possible?
What molecule is responsible for the catalytic activity in the spliceosomes that are involved in removal of introns?
Codons are a nearly universal language among all organisms.
Codons are three-base sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare?
before transcription is complete
Ribosomes can attach to prokaryotic messenger RNA ________.
concurrent transcription and translation
Which of the following occurs in prokaryotes, but not eukaryotes?
An anticodon forms hydrogen bonds with the codon; it must match the first two bases of the codon, but is less specific with respect to the third base.
There are 61 codons that each specify the addition of a specific amino acid, and three stop codons for which there is no corresponding amino acid. However, there are only about 40 tRNA molecules, representing 40 anticodons. How is that possible?
Inosine is a purine base that, when in an anticodon opposite the third base of a codon, provides flexibility in base pairing.
What is inosine, and what role does it play in translation?
1, 2, 3, 5, 4
Put the following events of elongation in prokaryotic translation in chronological order. 1. Binding of mRNA with small ribosomal subunit. 2. Recognition of initiation codon 3. Complementary base pairing between initiator codon and anticodon of initiator tRNA 4. Base pairing of the mRNA codon following the initiator codon with its complementary tRNA 5. Attachment of the large subunit
formation of a polypeptide bond
Which of the following is not one of the steps in initiation of translation?
the Shine-Dalgarno sequence.
The ribosome-binding site of prokaryotes is also known as
is a nonsense mutation
A mutation that results in premature termination of translation ________.