Molecular Genetics and Gene Expression Flashcards

Grade 12 · Science · Flashcards

Master key molecular genetics vocabulary for Grade 12 Science.

Flashcards

Central dogma: The flow of genetic information: DNA → RNA → Protein
Transcription: RNA polymerase copies DNA into mRNA; occurs in the nucleus of eukaryotes
Translation: Ribosomes read mRNA codons and assemble a polypeptide; occurs in the cytoplasm
Codon: A three-nucleotide sequence on mRNA encoding one amino acid; 64 possible codons
Anticodon: Three-nucleotide sequence on tRNA that base-pairs with the complementary mRNA codon
Intron: Non-coding sequence in pre-mRNA that is removed by splicing; does NOT appear in mature mRNA
Exon: Coding sequence retained in mature mRNA; translated into protein
RNA splicing: Removal of introns and joining of exons in pre-mRNA; performed by the spliceosome
Start codon: AUG — codes for methionine; initiates translation
Stop codons: UAA, UAG, UGA — terminate translation; no amino acid is added
Transcription factor: A protein that binds DNA regulatory sequences to activate or repress gene transcription
DNA methylation: Addition of methyl groups to cytosine bases; typically silences gene expression (epigenetic mechanism)