1/18/2016 3 Types of RNA 3 Types of RNA 1.Messenger RNA(mRNA) 2.Transfer RNA(tRNA) carries DNA coded message secondary structure (complementary copy)for making proteins creates loops message is in triplets called codons -bottom loop exposes a triplet of nucleotides C U G A U G A C U called the anticodon that 食息度息愈食息食愈 designates specificity and 866包8800 complements mRNA carries specific amino Codon 1 Codon2 Codon 3 acids to ribosomes P=Phosphate=Ribose U=Uracil a.IHNA-amino add 3 Types of RNA Transcription:The First Stage of Gene 3.Ribosomal RNA(rRNA) Expression component of ribosomes and participates in RNA polymerase binds to the promoter region protein synthesis providing peptidyl upstream of the gene transferase activity RNA polymerase adds RNA nucleotides complementary to the template strand of a segment of DNA in the 5'to 3'direction Suburits Uracil is placed as adenine's complement DNA 3'-ATGCAT would produce a 5'-UACGUA mRNA At termination,RNA polymerase recognizes signals in the sequence called the terminator and releases the transcript Short-term copies of the genes to be used to make proteins 305 1/18/2016 8 3 Types of RNA 1. Messenger RNA (mRNA) – carries DNA coded message ( mp m y py) f m g p complementary copy) for making proteins - message is in triplets called codons 3 Types of RNA 2. Transfer RNA (tRNA) - secondary structure creates loops - bottom loop exposes a triplet of nucleotides called the anticodon that designates specificity and complements mRNA - carries specific amino acids to ribosomes 3 Types of RNA 3. Ribosomal RNA (rRNA) - component of ribosomes and participates in protein synthesis providing peptidyl transferase activity Transcription: The First Stage of Gene Expression • RNA polymerase binds to the promoter region upstream of the gene • RNA polymerase adds RNA nucleotides complementary to the template strand of a segment of DNA in the 5′ to 3′ direction • Uracil is placed as adenine’s complement • DNA 3’-ATGCAT would produce a 5’-UACGUA mRNA • At termination, RNA polymerase recognizes signals in the sequence called the terminator and releases the transcript • Short-term copies of the genes to be used to make proteins