EVALUATION QUESTIONS AND ANSWERS
◉ TATA box Answer: a promoter region that contains a DNA
nucleotide sequence; its located ~25 nucleotide upstream from the
point at which transcription will begin
◉ RNA polymerases Answer: a family of enzymes that are
responsible for separating the DNA strands and chemical joining
together complementary RNA nucleotides that are added along the
length of the template DNA strand
◉ transcription factors Answer: assist with RNA polymerase binding
and facilitate the initiation of transcription; they are responsible for
controlling the rate of the mRNA transcription from the DNA
template strand
◉ transcription initiation complex Answer: the association of these
nucleotides' proteins
◉ what is the elongation process? Answer: o RNA polymerases glide
down the DNA template strand in the 3' to 5' direction
, o The polymerase unwinds the DNA in small sections and builds a
new complementary RNA strand to the DNA template strand
o When the RNA strand continues to grow it pulls away from the
DNA template allowing the DNA double helix to re-associate
◉ when does termination happen? Answer: after RNA strand has
been elongated along the DNA template strand
◉ polyadenylation sequence Answer: a sequence spanning 6
nucleotides in length that signals the end of transcription
◉ 5' cap Answer: a guanine nucleotide that has been modified by the
attachment of phosphates 20-40 nucleotides
◉ Poly-A-tail Answer: a series of 50-250 adenine nucleotides
◉ RNA splicing Answer: final modification of pre-mRNA that occurs
within the nucleus; it involves the removal and rejoining of the RNA
strand; the point of this removal and rejoining is to remove long
stretches of nucleotides that don't code for amino acids
◉ introns Answer: non-coding regions; found among the segments
that do encode for amino acids; spliced out during this phase