Practice Questions

The transcription bubble is the localized region of single-stranded DNA where RNA polymerase matches incoming ribonucleotides to the template.

Being single-stranded without a permanent complementary partner allows mRNA to remain dynamic and easily accessible to ribosomes.

Transcription initiation begins with a nucleoside triphosphate without clearing the pyrophosphate, leaving a 5'-triphosphate terminal.

Rho factor is an ATP-dependent helicase that tracks along the growing RNA transcript to unwind the RNA-DNA hybrid and terminate transcription.

A nonsense mutation converts an amino acid-specifying codon into a termination codon (UAA, UAG, or UGA), shortening the final protein.

Alpha-amanitin, a toxin from the death cap mushroom, is a highly specific inhibitor of eukaryotic RNA Polymerase II.

RNA viruses possessing RNA-dependent RNA polymerase can replicate their RNA directly from an RNA template without creating a DNA intermediate.

The 23S rRNA located in the large (50S) prokaryotic ribosomal subunit acts as the peptidyl transferase ribozyme.

The chemical reactivity of the 2'-OH group allows RNA to participate in catalytic mechanisms, giving rise to ribozymes.

Transcription produces an RNA strand complementary and anti-parallel to the DNA template strand, replacing thymine with uracil.