Protein Synthesis

Learning Goals What to know: Relationship between DNA, genes, amino acids, and proteins DNA vs RNA Steps of transcription & translation Coding for specific amino acids

Gene Expression Protein- is a long string of amino acids that fold into various structures Gene: segment of DNA that specifies the amino acid (AA) sequence of a protein

Production of RNA RNA- Ribonucleic Acid This is not making a mRNA on the ENTIRE DNA strand…..JUST THE GENE link between DNA & Protein synthesis single strand, single helix, Uracil not Thymine

Something new you learned Something surprising you learned Watch linked video In your notes: Something new you learned Something surprising you learned A question you still have

DNA makes RNA in nucleus 3 types of RNA: 1. Messenger (mRNA)- takes DNA message to ribosome 2. Ribosomal (rRNA) - make up ribosome (with proteins) 3. Transfer (tRNA) - brings amino acids to ribosomes

Protein Synthesis Steps Gene Expression- production of a protein 2 steps: 1. Transcription- DNA copied into mRNA 2. Translation- mRNA directs the sequence of AA in a polypeptide

Part 1 - Transcription Transcription of mRNA RNA Polymerase binds tightly to Promoter (TATA box) Promoter is a region of DNA that contains special sequence of nucleotides RNA Polymerase opens open DNA & joins RNA nucleotides to DNA (complimentary)

Transcription Cont’d -Processing- Add Guanine cap to 5’ end of RNA and Poly-A tail (AAAAAA) to 3’ end of RNA Introns, segments of DNA with no gene function, are cut out leaving only exons get to leave nucleus Exons spliced together is the finished RNA strand

Transcription Steps

Part 2 - Translation mRNA goes to ribosome The mRNA tells what order the amino acids should be in to make the protein

Translation The Code Codon- 3 letters unit of mRNA 64 different codons but only 20 different aa You will get handout

Translation b) Transfer RNA (tRNA) Bring the amino acid (aa) to the ribosomes at least 1 tRNA molecule for each of 20 aa aa binds to one end of tRNA Other end has anticodon which is complimentary to a specific codon of mRNA RNA-amino acid complex goes to ribosome and its anticodon pairs with mRNA codon

Translation 1. Initiation 2. Elongation 3. Termination

Let’s practice reading the code: DNA is: 3’TATAGTACAATACTGAACATTUCTTGC5’ What is the mRNA? What is the amino acid sequence?

Crafty Time  Each table team will get a ziplock bag of protein synthesis parts “act out” the process of protein synthesis using the paper pieces Complete the attached booklet with the codes that you create

Video Time You are going to make a video showing your understanding of protein synthesis You will work in partners You can use the ipads to create either a whiteboard marker sped up video, or a playdough video (see samples)

Video Samples Due to watch Monday, Oct 15th at START of class Whiteboard video Playdough video Due to watch Monday, Oct 15th at START of class

Apps to Use for Video