Transcription Steps to Transcribe DNA: The process by which DNA is copied to RNA Involves an enzyme called RNA Polymerase Steps to Transcribe DNA: RNA Polymerase attaches to DNA at a sequence called the promoter DNA strand separates temporarily RNA polymerase adds RNA nucleotides to the DNA template RNA polymerase travels along template strand

Transcription RNA polymerase continues to read from 3’ to 5’ until it reaches a point on the DNA strand called a termination signal. DNA helix strand joins back together Only separates when RNA polymerase is attached

Translation The process by which mRNA is “read” and translated into a protein 3 Types of RNA are needed: mRNA: messenger RNA tRNA: transfer RNA rRNA: ribosomal RNA Translation begins at a start codon (AUG) Ends at a stop codon (UAA, UAG, UGA)

Translation Start codon always codes for the amino acid methionine 3 Stages of Translation: Initiation Elongation Termination Initiation: rRNA attaches to mRNA at the start codon (AUG) tRNA with UAC anticodon and methionine amino acid attaches to mRNA at AUG rRNA attaches to mRNA over the tRNA

Translation Elongation: tRNA matching next codon attaches to empty codon on mRNA Peptide bond forms between the 2 amino acids Ribosome (rRNA pieces) moves toward the 3’ direction First tRNA drops off and leaves amino acid Repeats until “STOP” codon is reached.

Translation Termination: Ribosome reaches the stop codon tRNA will never match a stop codon Last tRNA is released, along with protein Ribosome detaches into 2 rRNA pieces All parts are now in the cytoplasm floating freely

Overview