Term | Definition |
Transcription | The synthesis of RNA using a DNA template. |
mRNA | A type of RNA, synthesized using a DNA template, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein. |
Translation | The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. |
Ribosome | A complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm; consists of a large and a small subunit. |
Codon | A three-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code. |
RNA Polymerase | An enzyme that links ribonucleotides into a growing RNA chain during transcription, based on complementary binding to nucleotides on a DNA template strand. |
Promoter | A specific nucleotide sequence in the DNA of a gene that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place. |
Terminator | 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. |
Transcription Unit | A region of DNA that is transcribed into an RNA molecule. |
TATA Box | A DNA sequence in eukaryotic promoters crucial in forming the transcription initiation complex. |
Introns | A non-coding, intervening sequence within a primary transcript that is removed from the transcript during RNA processing. |
Exons | A sequence within a primary transcript that remains in the RNA after RNA processing. |
tRNA | An RNA molecule that functions as a translator between nucleic acid and protein languages by carrying specific amino acids to the ribosome, where they recognize the appropriate codons in the mRNA. |
rRNA | RNA molecules that, together with proteins, make up ribosomes; the most abundant type of RNA. |
Mutation | A change in the nucleotide sequence of an organism’s DNA or in the DNA or RNA of a virus. |
Mutagen | A chemical or physical agent that interacts with DNA and can cause a mutation. |