1. Dna Transcription & Translation Presented by: Lulu Tesha Rahshad Cobb

2. Why DNA transcription/Translation is needed! DNA transcription and translation is needed when the cell needs more protein! If you remember from the video notes the “Central Dogma of Molecular Biology” (5 th page in video notes.) : –Information flows from DNA to mRNA to proteins. –Genetic info is stored in DNA! –Information flows from DNA to RNA during Transcription –Information is then coded into proteins during Translation.

3. What is DNA Transcription? Also known as RNA synthesis, DNA transcription is a process where DNA changes genetic info from DNA to RNA. DNA consists of four nucleotide bases: Adenine (A) Guanine (G) Cytosine (C) Thymine (T) These are paired together (A-T and C-G) to give DNA its double helix shape.

4. RNA Structure RNA/ mRNA / tRNA etc… contains the nucleotides: Adenine Guanine Cytosine Uracil (U) (Replaces thymine) Guanine pairs with Cytosine and Adenine pairs with Uracil. (G-C and A-U) After Transcribing DNA, it is now mRNA

5. Example! DNA Strand: G T G C A T C T G A C T C A C G T A G T C T G A Transcription (mRNA strand) [G U G] [C A U] [C U G] [A C U] Translation! (tRNA strand) (Uracil is replaced with adenine) [C A C] [G U A] [G A C] [T G A]

6. Translation Details (Codons) During DNA translation, a ribosome reads the strand of mRNA. After reading, an anticodon (Carried by transfer RNA (tRNA)) is bound temporarily to the first three nucleotides. Each group of three nucleotides is a single codon.

7. Translation continued… After the anticodon reads the first three nucleotides, the next set is read. The process continues as the tRNA brings another anticodon to the second set of nucleotides. The two codons then bond to each other with a peptide bond

8. Translation Final When the ribosome scans the third set of codons, and the tRNA brings in the next anticodon. The first tRNA bond breaks off leaving its amino acid. * This process continues until the ribosome reads the “Stop” codon (UAA). This codon indicates the end of the gene. The last tRNA falls off the ribosome and the ribosome leaves the mRNA strand. (*) Since the tRNA leaves its amino acid after it breaks off, there is a chain of amino acids leftover after the process is complete.

9. Dna Transcription & Translation Animation The brief flash animation of DNA Transcription and translation is shown at this link. http://www- class.unl.edu/biochem/gp2/m_biology /animation/gene/gene_a3.htmlhttp://www- class.unl.edu/biochem/gp2/m_biology /animation/gene/gene_a3.html Click?

10. Bibliography “Animation” Deana Namuth (2000) “Protein Synthesis: Transcription and translation”