General Biology Notes
TRANSLATION
A.K.A. PROTEIN SYNTHESIS

• the process of converting or translating the information in mRNA into a sequence of amino acids that makes up proteins.

• Before translation can begin, transcription of the DNA into mRNA must occur.

There are three types of RNA involved in protein synthesis:

1. Initiation: mRNA attaches to the ribosome (rRNA). (The rRNA slides along the mRNA like a bead on a string.)

• rRNA “ reads ” the mRNA in groups of three nucleotides called a codon .
• Translation always begins with a special codon ( AUG ) called the initiator or start codon.

• there are 20 different amino acids and
64 different codons. Each amino acid may have more than one codon but each codon specifies for only one amino acid.

• Transfer RNA (tRNA) carries or “ taxis ”a specific amino acid determined by the anticodon to the ribosome .
• The anticodon of tRNA pairs with the complementary codon on mRNA.

• As the tRNA’s line up the amino acids, peptide bonds form between amino acids linking them into a protein.

• The tRNA’s are recycled back to pick up more amino acids.

• the protein is released from the ribosome when a “ stop ” codon is reached. There are three special “stop” codons: UAA,
UAG and UGA