Protein Synthesis Lab How Proteins Are Constructed

2 The Central Dogma of Molecular Biology Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. nontemplate strand 3' 5' AGGGACCCC TCGCTGGGG 3' template strand transcription in nucleus 3' 5' mRN DNA AGGGACCCC codon 1codon 2codon 3 polypeptide translation at ribosome NN N CCC C CC R1R1 R2R2 R3R3 SerineAspartateProline OOO

3 Types of RNA  RNA is a polymer of RNA nucleotides  RNA Nucleotides are of four types: Uracil, Adenine, Cytosine, and Guanine  Uracil (U) replaces thymine (T) of DNA  Types of RNA  Messenger (mRNA) - Takes genetic message from DNA in nucleus to ribosomes in cytoplasm Messenger (mRNA)  Ribosomal (rRNA) - Makes up ribosomes which read the message in mRNA Ribosomal (rRNA)  Transfer (tRNA) - Transfers appropriate amino acid to ribosome when “instructed” Transfer (tRNA)

4 Transcription Gene unzips and exposes unpaired bases Serves as template for mRNA formation RNA nucleotides bind to exposed DNA bases using the C=G & A=U rule Entire gene is transcribed into mRNA Base sequence in mRNA is complementary to the base sequence in DNA

5 Transcription Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. nontemplate strand template strand 5' C CG T A AT G C A A C G T C T C U G G A C C A C A T G G C RNA polymerase DNA template strand mRNA transcript C G C AT CG TA to RNA processing 3' 5'

Animation 6 Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at

7 Translation  tRNA molecules bring amino acids to the ribosome Ribosome reads a codon in the mRNA  Anticodon complementary to the mRNA codon  Joins the ribosome at A site Methionine connected to amino acid of 2 nd tRNA by peptide bond Stop codon halts process

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Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at

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