1. The Genetic Code Objective: F2 - Explain … process of transcription & translation …, describe the role of DNA & RNA during protein synthesis, & recognize that gene expression is a regulated process

2. Using the Genetic Code A. Codon – 3 nitrogen bases of mRNA in a row that code for a specific amino acid B. Genetic code – a chart that shows the amino acids that correspond to the codons of mRNA

3. C. How nucleotides are read – 3 at one time 1.3 DNA nucleotides = CAT 2. 3 mRNA nucleotides = 3.tRNA nucleotides = CAU GUA

4. D. Reading the Genetic Code 1. 1st letter (base) of the codon = G 2. 2nd letter (base) of the codon = U 3. 3rd letter (base) of the codon = A Using the genetic code on the front, which amino acid does the above codon produce? ________ Valine

5. E. To “make” a protein 1. Transcribe the given DNA strand into mRNA 2. Look up the mRNA codons on the Genetic Code table

6. Practice: DNA sequenceTAC AAA GTA TGG GGC ATC 1. Transcribe into mRNA 2. Translate into an amino acid sequence AUG UUU CAU ACC CCG UAG Met- Phe- His- Thr- Pro- stop

7. DNA mRNA codon tRNA anticodon Amino acid 4.Tryptophan (TRP) 5.AGA 6.TTT 7.UGA UGGACCACC UCUAGASerine AAAUUULysine ACTACU Stop

8. Although there are only 20 amino acids in the human body, thousands of proteins exist because the sequence and number of amino acids are different.