Ch. 17 Vocab Flashcards
the synthesis of RNA using a DNA template
transcription
a type of RNA, synthesized using a DNA template, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein
mRNA
the synthesis of a polypeptide using the genetic information encoded in an mRNA molecule
translation
the sugar component of RNA nucleotides
ribosomes
a set of three-nucleotide-long words that specify the amino acids for polypeptide chains
triplet code
the DNA strand that provides the pattern, or template, for ordering the sequence of nucleotides in an RNA transcript
template strand
an enzyme that links ribonucleotides into a growing RNA chain during transcription
RNA polymerase
a specific nucleotide sequence in DNA that binds RNA polymerases positioning it to start transcribing RNA at the appropriate place
promoter
in bacteria, a sequence of nucleotides in DNA that marks the end of a gene and signals RNA polymerase to release the newly made RNA molecule and detach from the DNA
terminator
a regulatory protein that binds to DNA and affects transcription of specific genes
transcription factors
modification of RNA transcripts, including splicing out introns, joining together of exons, and alteration of the 5’ and 3’ ends
RNA processing
a noncoding, intervening sequence within a primary transcript that is removed from the transcript during RNA processing
introns
a sequence within a primary transcript that remains in the RNA after RNA processing
exon
a large complex made up of proteins and RNA molecules that splices RNA by interacting with the ends of an RNA intron, releasing the intron and joining the two adjacent exons
spliceosome
a type of eukaryotic gene regulation at the RNA-processing level in which different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns
alternative RNA splicing
an independently folding part of a protein
domains
an RNA molecule that functions as an interpreter between nucleic acid and protein language by picking up specific amino acids and recognizing the appropriate codons in mRNA
tRNA
a nucleotide triplet at one end of a tRNA molecule that recognizes a particular complementary codon on an mRNA molecule
anticodon
flexibility in the base-pairing rules in which the nucleotide at the 5’ end of a tRNA codon can form hydrogen bonds with more than one kind of base in the third position of a codon
wobble
the most abundant type of RNA, which together with proteins makes up ribosomes
rRNA
holds the tRNA carrying the next amino acid to be added to the polypeptide chain
A site
holds the tRNA carrying the growing polypeptide chain
P site
the place where discharged tRNAs leave the ribosome
E site
a group of several ribosomes attached to, and translating, the same messenger RNA molecule
polyribosome
a change in the nucleotide sequence of an organism’s DNA, ultimately creating genetic diversity
mutation
a change in a gene at a single nucleotide pair
point mutation
a base-pair substitution that results in a codon that codes for a different amino acid
missense mutation
a type of point mutation; the replacement of one nucleotide and its partner in the complementary DNA strand by another pair of nucleotides
base-pair substitution
a mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein
nonsense mutation
a mutation involving the addition of one or more nucleotide pairs to a gene
insertion
a mutational loss of one or more nucleotide pairs from a gene
deletion
a mutation occurring when the number of nucleotides inserted or deleted is not a multiple of three, resulting in the improper grouping of the subsequent nucleotides into codons
frameshift mutation
a chemical or physical agent that interacts with DNA and causes a mutation
mutagens
the process by which DNA directs the synthesis of proteins, or, in some cases, just RNAs
gene expression
