A site
ribosome binding site where a charged tRNA associated with an amino acid first attaches
activator
protein that increases transcription of a gene
aminoacyl-tRNA synthetase
enzyme that attaches an amino acid to a tRNA molecule
anticodon
sequence of three nucleotides of a tRNA molecule that pairs with the complement on an mRNA strand during protein synthesis
central dogma of biology
concept that genetic information flows from DNA to RNA to proteins
E site
ribosome binding site where the tRNA is ejected following translation
enhancer
region of DNA that encourages transcription by binding proteins that help initiate it
exon
DNA sequence within a gene sequence that codes for a polypeptide sequence. Exons must be combined during mRNA processing.
intron
DNA sequence within a gene sequence that does not code for a specific protein. Introns must be removed from the pre-mRNA during processing.
lac operon
gene cluster that codes for enzymes that import and digest the sugar lactose in E. coli and other bacteria
messenger RNA (mRNA)
RNA molecule made from a DNA template, contains the complementary gene sequence, that is, the sequence opposite to the DNA strand
operon
collection of genes that are transcribed together and contain at least two regions of control, called a promoter and an operator
P site
ribosome binding site where an amino acid is added to the growing peptide chain
pluripotent stem cell
cell able to reproduce indefinitely and develop into other types of specialized cells
polyadenylation
addition of a poly-A tail, or multiple adenosine monophosphates, to an mRNA strand
promoter
sequence of DNA to which RNA polymerase binds to initiate the process of transcription
protease
enzyme that functions in protein degradation
proteasome
enzyme complex that modifies or degrades a protein
proteome
proteins expressed by the genome of an organism or a cell throughout its life or at a specified time under certain environmental conditions
regulatory DNA sequence
nucleotide sequence that can increase or decrease gene expression
repressor
protein that inhibits transcription of a gene
ribosomal RNA (rRNA)
RNA component of ribosomes that catalyzes peptide bond formation
RNA polymerase
enzyme used in the formation of RNA
RNA splicing
process by which introns are removed from mRNA and exons are joined together following transcription
terminator
stop signal on the DNA strand that halts synthesis of mRNA
transcription
formation of messenger RNA from the template DNA strand to be used to build proteins
transcription factor
protein that binds to the regulatory DNA sequence to control transcription
transfer RNA (tRNA)
molecule that carries each amino acid to the strand of mRNA during translation of protein synthesis
translation
assembly of amino acids into proteins in ribosomes through the reading of mRNA by tRNA and the ribosome