Practice Questions

Hydrogen bonds are weak non-covalent interactions, allowing the twin strands to unzip easily when driven by specialized enzymes.

A missense mutation alters a single nucleotide, changing a codon so that it incorporates a different amino acid into the protein.

The promoter is a specific upstream nucleotide sequence that signals the transcription machinery where to start making RNA.

Placing the charged, polar groups on the outside allows DNA to interact favorably with the watery environment of the nucleoplasm.

Human genes contain introns, which bacteria cannot slice out because they lack spliceosomes, leading to a flawed, non-functional protein.

DNA polymerases require a free 3'-OH group to form a phosphodiester bond with the 5' phosphate group of an incoming dNTP.

Transcription generates an RNA transcript that is complementary and anti-parallel to the DNA template strand, swapping thymine for uracil.

Introns are intervening, non-translated sequences within a gene that are transcribed into pre-mRNA but removed by splicing.

G-C pairs are linked by three hydrogen bonds, which require more thermal energy to disrupt than the two hydrogen bonds holding A-T pairs together.

With 10 base pairs per complete helical turn of 3.4 nm, the step distance between consecutive base pairs is 3.4/10=0.34 nm.