The process by which DNA directs the synthesis of proteins or, in some cases, just RNAs.
messenger RNA (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.
The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of "language" from nucleotides to amino acids.
A complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm; in eukaryotic cells, each subunit is assembled in the nucleolus. See also nucleolus.
An initial RNA transcript; also called pre-mRNA when transcribed from a protein-coding gene.
A set of three-nucleotide-long words that specify the amino acids for polypeptide chains.
The DNA strand that provides the pattern for ordering the sequence of nucleotides in an RNA transcript.
A three-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code.
On an mRNA, the triplet grouping of ribonucleotides used by the translation machinery during polypeptide synthesis.
A specific nucleotide sequence in DNA that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place.
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.
A regulatory protein that binds to DNA and affects transcription of specific genes.
transcription initiation complex
the completed assembly of transcription factors and RNA polymerase bound to a promoter
a DNA sequence in eukaryotic promoters crucial in forming the transcription iniation complex
Modifications of RNA transcripts, including splicing out of introns, joining together of exons, and alterations of the 5' and 3' ends
A modified form of guanine nucleotide added on to the nucleotide at the 5' end of a pre-mRNA molecule
A sequence of 50 to 250 adenine nucleotides added on to the 3' end of a pre-mRNA molecule
after synthesis of a eukaryotic primary RNA transcript, the removal of portions (introns) of the transcript that will not be included in the mRNA
a noncoding, intervening sequence within a primary transcript that is removed from the transcript during RNA processing; also refers to the region of the DNA from which this sequence was transcribed
a sequence within a primary transcript that remains in the RNA after RNA processing; also refers to the region of the DNA from which this sequence was transcribed
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 adajcent exons
alternative RNA splicing
a type of eukaryotic gene regulation at the RNA-processing level in which different mRNA molcules are produced from the same primary transcript depending on which RNA segments are treated as exons and which as introns
transfer RNA (tRNA)
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 the mRNA
a nucleotide triplet at one end of a tRNA molecule that recognizes a particular complementary codon on an mRNA molecule
flexibility in the base-pairing rules in which the nucleotide at the 5' end of a tRNA anticodon can form hydrogen bonds with more than one kind of base in the third position (3' end) of a codon
one of a ribosome's three binding site for tRNA during translation. It holds the tRNA carrying the next amino acid to be added to the polypeptide chain
one of a ribosome's three binding site for tRNA during translation. It is the place where discharged tRNAs leave the ribosome
one of a ribosome's three binding sites for tRNA during translation. it holds the tRNA carrying the growing polypeptide chain.
a group of several ribosomes attatched to, and translating, the same messenger RNA molecule
a sequence of about 20 amino acids at or near the leading amino end of a polypeptide that targets it to the endoplasmic reticulum or other organelles in a eukaryotic cell
signal-recognition particle (SRP)
a protein-RNA complex that recognizes a signal peptide as it emerges from a ribosome and helps direct the ribosome to the endoplasmic reticulum (ER) by binding to a receptor protein on the ER
a change in the nucleotide sequence of an organism's DNA, ultimately creating genetic diversity. It can also occur in the DNA or RNA of a virus
a type of point mutation; the replacement of one nucleotide and its partner in the complementary DNA strand by another pair of nucleotides
a base-pair subsitution that results in a codon that codes for a different amino acid
a mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein
a mutation occuring 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