http://www.ebsi.co.kr/ebs/lms/lmsx/retrieveSbjtDtl.ebs?sbjtId=S20180001029 ================================================================================ The central dogma of gene information = mechanism of gene information flowing ================================================================================ 1. Transcription, mRNA is partial copy from DNA 2. Translation ================================================================================ Triplet code: 3 number of base can specify "one amino acid" For example, AAA can specify "Lysine" * Following is not true one triplet code : one amino acid There are multiple triplet code which can specify one amino acid For example, AAA and AAG specify "Lysine" ================================================================================ Triplet code and codon ================================================================================ Language of mRNA: codon, codon table Codon of UUU and UUC specify Phenylalanine ================================================================================ Since codon is UUU, "Phenylalanine" (green square) is brought to the ribosome by tRNA ================================================================================ The shape of tRNA 3 tails are called "anti-codon" Triplet code <--complementary--> codon <--complementary--> anti-codon ================================================================================ tRNA which has AAA anti-codon, which has Phenylalanine ================================================================================ Be careful on the direction ================================================================================ Methionine which is specified by AUG is the start codon which starts the synthesizing the protein The first amino acid in polypeptide is methionine ================================================================================ Summary on the codon - 64 number of codon - Methionine: start codon, specified by AUG - End codon: UAA, UAG, UGA ================================================================================ The detail of tRNA - The language of tRNA: anti-codon - First, see the codon in mRNA - Codon --hydrogen bond-- anti-codon - tRNA is single strand but in some parts, tRNA can have complementary hydrogen bond by itself - Be careful on the direction - Find AUG in codon table, AUG specifies methionine - Note that amino acid is attached onto 3' ================================================================================ Example - DNA template strand - Perform transcription - mRNA strand - See the codon table Methionine - Lysine - Phenylalanine - Tryptophan - (End-codon) - Codon: 5 ones - Number of amino acid: 4 ones - Number of peptidie bond: 3 times ================================================================================