HBio: Protein synthesis

ribosome

cellular structure that carries out protein synthesis

transcription

a process through which messenger RNA forms on a template of DNA

gene

physical and functional unit of heredity, a sequence of DNA that codes for a protein. a section of the genome.

anticodon

three-nucleotide sequence in a tRNA molecule that corresponds to an mRNA codon

start codon

AUG (or rarely, GUG) on an mRNA from which translation begins; always specifies methionine

exon

the sequence present in protein-coding mRNA after completion of pre-mRNA splicing

messenger RNA (mRNA)

RNA that carries information from DNA to ribosomes during protein synthesis

translation

process through which RNA directs the protein’s formation

RNA polymerase

an enzyme that synthesizes RNA primer in the 5’ to 3’ direction to allow DNA polymerase to start the replication process

complementary strand

the strand of DNA that is not used to transcribe mRNA. this strand is used for storage to allow the double helix to rewind.

stop codons

three mRNA codons that terminate protein synthesis and release the polypeptide from the translation machinery

intron

non-protein-coding intervening sequences that are spliced from mRNA during processing

transfer RNA (tRNA)

RNA that carries activated amino acids to the site of protein synthesis on the ribosome

amino acid

a protein’s monomer; has a central carbon bonded to an amino group, a carboxyl group, a hydrogen atom, and an R group

codon

three consecutive nucleotides in mRNA that specify the insertion of an amino acid or the release of a polypeptide chain during translation

coding strand

the strand of DNA that determines the complementary mRNA molecule

degeneracy

describes that a given amino acid can be encoded by more than one nucleotide triplet. each codon only has one amino acid.

spliceosomes

bind to the signals that mark the exon/intron border to remove the introns and ligate the exons together. allows the start of the translation process.