Genes and Proteins Flashcards
7-methylguanosine cap
modification added to the 5’ end of pre-mRNAs to protect mRNA from degradation and assist translation
Aminoacyl tRNA synthetase
enzyme that “charges” tRNA molecules by catalyzing a bond between the tRNA and a corresponding amino acid
Anticodon
three-nucleotide sequence in a tRNA molecule that corresponds to an mRNA codon
CAAT box
(GGCCAATCT) essential eukaryotic promoter sequence involved in binding transcription factors
Central dogma
states that genes specify the sequence of mRNAs, which in turn specify the sequence of proteins
Codon
three consecutive nucleotides in mRNA that specify the insertion of an amino acid or the release of a polypeptide chain during translation
Colinear
in terms of RNA and protein, three “units” of RNA (nucleotides) specify one “unit” of protein (amino acid) in a consecutive fashion
Consensus
DNA sequence that is used by many species to perform the same or similar functions
Core enzyme
prokaryotic RNA polymerase consisting of α, α, β, and β’ but missing σ; this complex performs elongation
Degeneracy
(of the genetic code) describes that a given amino acid can be encoded by more than one nucleotide triplet; the code is degenerate, but not ambiguous
Downstream
nucleotides following the initiation site in the direction of mRNA transcription; in general, sequences that are toward the 3’ end relative to a site on the mRNA
Exon
sequence present in protein-coding mRNA after completion of pre-mRNA splicing
FACT
complex that “facilitates chromatin transcription” by disassembling nucleosomes ahead of a transcribing RNA polymerase II and reassembling them after the polymerase passes by
GC-rich box
(GGCG) nonessential eukaryotic promoter sequence that binds cellular factors to increase the efficiency of transcription; may be present several times in a promoter
Hairpin
structure of RNA when it folds back on itself and forms intramolecular hydrogen bonds between complementary nucleotides
Holoenzyme
prokaryotic RNA polymerase consisting of α, α, β, β’, and σ; this complex is responsible for transcription initiation