BSC1010 7.4 to 7.8 vocabulary

template strand

the strand in a DNA double helix that is transcribed

RNA polymerase

enzyme that uses a DNA template to produce a molecule of RNA

promoter

a control sequence at the start of a gene; attracts RNA polymerase and (in eukaryotes) transcription factors

intron

portion of an mRNA molecule that is removed before translation

exon

portion of an mRNA that is translated after introns are removed

somatic mutation

occurs in nonsex cells, does not pass from generation to generation

anticodon

a three-base portion of a tRNA molecule; the anticodon is complementary to one codon

ribosome

a structure build of RNA and protein where mRNA anchors during protein synthesis

mutation

a change in a DNA sequence

point mutation

a gene mutation involving the substitution, addition, or deletion of a single nucleotide base

substitution

a mutation where one DNA bases is replaced with another

frameshift mutation

type of mutation in which nucleotides are added or deleted by any number other than a multiple of three, altering the reading frame

expanding repeat mutation

type of mutation in which the number of copies of a three- or four- nucleotide sequence increases over several generations

mutagen

any external agent that causes a mutation