| Term | Definition |
| anticodon | a three nucleotide on t RNA that recognizes a complimentary codon on m RNA |
| codon | a three nucleotide in DNA or mRNA that encodes an amino acid or signifies a stop signal |
| exon | sequence of nucleoclides on a gene that gets transcribed and translated |
| gene expression | two-stage processing of information in DNA to produce proteins |
| genetic code | sequence of nucleotides that specifies the amino acid of a protein |
| intron | segment of mRNA transcribed from eukaryotic DNA but removed before translation of mRNA into a protein |
| lac operon | gene system with a promoter, an operator gene, and three structural genes that control lactose metabolism |
| messenger RNA | RNA copy of a gene used as a blueprint for the making of a protein during translation |
| operator | region of DNA that controls RNA polymerase's access to a set of genes with related functions |
| operon | segment of DNA that controls gene regulation in a set of genes with related functions in prokaryotes |
| point mutation | mutation in which one or just a few nucleotides in a gene are changed |
| repressor | protein that binds to the operator in an operon to switch off transcription |
| ribonucleic acid | a type of nucleic acid involved protein synthesis |
| ribosomal RNA | type of RNA molecule that plays a structural role in ribosomes |
| RNA polymerase | enzyme that adds and links complimentary RNA nucleotides during transcription |
| transcription | stage of protein synthesis in which the information in DNA for making a protein is transferred to an RNA molecule |
| transfer RNA | RNA molecule that temporarily caries a specific amino acid to a ribosome during translation |
| translation | stage of gene expression in which the information in mRNA is used to make a protein |
| uracil | nitrogen-containing base of RNA complimentary adenine when RNA base pairs with DNA |