1. 11.5 NOTES: DNA TRANSLATION

3. 11.5 Notes: DNA Translation What does it mean to Translate? Translating the nucleic acid language to the protein language….using codons Codons: “ 3-base word ” that codes for 1 amino acid Several codons form a “ sentence ” that translates into a polypeptide (made up of several amino acids-which build proteins) Proteins: work together to perform a particular function

4. DNA Translation All codons code for amino acids EXCEPT 3. There are 3 “ stop codons ” (UAA, UAG, UGA) that come at the end of each gene sentence – Kind of like a period at the end of a sentence—causes the amino acid/polypeptide chain to fall off —because it ’ s finished. – Also notice that there is 1 “ start codon ” (AUG – which codes for methionine)

5. Review ALL of repliction/transcription/translation on board

7. DNA Translation Where: Cytoplasm Who: Transfer RNA (tRNA): translates the 3- base codons of mRNA to the amino acid it codes for. (it brings in the appropriate amino acid) Anticodon : the 3 bases attached to the tRNA who will complementary bind to the specific codon on the mRNA strand

9. DNA Translation Ribosome : an organelle that makes proteins (coordinates the functioning of mRNA and tRNA) – It consists of 2 subunits …which hold the mRNA and tRNA molecules together during translation. * Ribosomal RNA (rRNA) : RNA inside of a ribosome

10. DNA Translation HOW? Translation Details: Step 2 of protein synthesis 1. mRNA meets up with ribosome and bind together 2. Ribosome “ reads ” along mRNA until it reaches a “ start codon ” (AUG) Meanwhile… tRNA molecules are binding with their corresponding amino acids (according to the codon chart)

11. DNA Translation 4. Once the ribosome reaches a “ start codon ”, translation begins. (only 2 complete codons fit into a ribosome at one time) 5. The tRNA with the anticodon, UAC, complementary binds to the “ start codon ” bringing along its amino acid, Methionine (MET)

12. DNA Translation 6. The 2 nd mRNA codon in the ribosome gets paired with its corresponding anticodon on another tRNA molecule, bringing along another amino acid. 7. The 2 amino acids will attach to start a growing amino acid chain.

14. DNA Translation 8. Significance: the entire gene has been expressed and the desired protein is completely made and released to where it needs to go into the body.