Protein Synthesis

transcription

the process whereby the DNA sequence in a gene is copied into mRNA

translation

the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome

mRNA

molecule synthesized from DNA that attaches to ribosomes and specifies the primary structure of a protein

tRNA

molecule that delivers amino acids to the ribosome during translation

codon

a specific sequence of three adjacent bases on a strand of mRNA that codes for a particular amino acid

anticodon

a group of three bases on a tRNA molecule that are complementary to an mRNA codon

RNA polymerase

Enzyme that binds to DNA and synthesizes mRNA during transcription

spliceosome

an enzyme that removes introns and joins exons

poly-A tail

a modified end of the 3' end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides

5' cap

a cover that is added to the 5' end of mRNA before mRNA leaves the nucleus

dNTP

free nucleotides that carry three phosphate groups (deoxynucleotide triphosphate)

aminoacyl-tRNA synthase

an enzyme that joins each amino acid to the appropriate tRNA

methionine

amino acid that is the 'start' of a polypeptide sequence

A site

region in a ribosome that binds incoming aminoacyl-tRNA molecules

P site

region in ribosome where peptide bond is formed adding amino acid to the chain

E site

region of ribosome where discharged tRNA's leave the ribosome

ribosome

cytoplasmic organelles where proteins are synthesized

AUG

start codon

UGA, UAA or UAG

stop codons

amino acid

monomer unit of proteins