Protein Synthesis - Translation
Translation is the process through which information carried by mRNA is turned into actual proteins by ribosomes. Translation takes place in three steps:
1. Initiation - mRNA leaves the nucleus and initiation factors help the start codon (see below) AUG on mRNA bind to the small subunit of a ribosome. tRNA (transfer RNA) carries in the corresponding anticodon and the amino acid Methionine. A large subunit of the ribosome arrives and places the tRNA into its P-site. 2. Elongation - Next, elongation factors bring the next corresponding tRNA to the A-site of the large subunit. The enzyme Peptidyl Transferase connects the two amino acids and a peptide bond forms between them. This also detaches the tRNA from the ribosome's P-Site and from its Amino Acid.
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3. Termination - Elongation continues until the ribosome reaches a stop codon (UAA, UAG, or UGA). Because there is no corresponding tRNA to match up with the stop codon the ribosome will simply stop transcribing. Releasing Factors will come along and detach the last amino acid from tRNA. The mRNa will float away and coil into its tertiary shape.
Listen to the video on the Right to hear Mr. Roisen review Translation for you ---> |
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Translation Video: http://www.youtube.com/watch?v=TfYf_rPWUdY&feature=relmfu
Roisen Review Video: http://www.youtube.com/watch?v=mvV9LSUbm8g&list=PL9CAF3DEF0A718A50&index=51&feature=plpp_video
Picture: http://www.google.com/imgres?q=dna+translation+diagram&hl=en&sa=X&biw=1024&bih=620&tbm=isch&tbnid=ZawAUr3HcZuooM:&imgrefurl=http://cr4.globalspec.com/blogentry/9511/The-Chemistry-of-DNA-Part-4&docid=NBkRLTXoOdooBM&imgurl=http://cr4.globalspec.com/PostImages/200912/peptide_B7D083B7-A007-B1C8-B4C438E923FFAB3E.jpg&w=400&h=338&ei=WvWUT6WnKOPiiALT94QW&zoom=1&iact=hc&vpx=741&vpy=43&dur=7505&hovh=206&hovw=244&tx=173&ty=183&sig=109968161131638774347&page=1&tbnh=129&tbnw=156&&ndsp=17&ved=1t:429,r:5,s:0,i:91
Roisen Review Video: http://www.youtube.com/watch?v=mvV9LSUbm8g&list=PL9CAF3DEF0A718A50&index=51&feature=plpp_video
Picture: http://www.google.com/imgres?q=dna+translation+diagram&hl=en&sa=X&biw=1024&bih=620&tbm=isch&tbnid=ZawAUr3HcZuooM:&imgrefurl=http://cr4.globalspec.com/blogentry/9511/The-Chemistry-of-DNA-Part-4&docid=NBkRLTXoOdooBM&imgurl=http://cr4.globalspec.com/PostImages/200912/peptide_B7D083B7-A007-B1C8-B4C438E923FFAB3E.jpg&w=400&h=338&ei=WvWUT6WnKOPiiALT94QW&zoom=1&iact=hc&vpx=741&vpy=43&dur=7505&hovh=206&hovw=244&tx=173&ty=183&sig=109968161131638774347&page=1&tbnh=129&tbnw=156&&ndsp=17&ved=1t:429,r:5,s:0,i:91