2. Introduction to Genetics: DNA Grades 9-12 Matt Cardinal

3. Where is DNA? Most Organisms in the world have DNA It plays an important role on the function of an organism DNA is found in cells and all animals are made up of cells DNA is located in the nucleus of a cell

4. Structure of DNA James Watson and Francis Crick – 1953 Double Helix shape – Allows it to be easily opened and closed Composed of nucleotide bases, sugars, and phosphates Four bases are: adenine, cytosine, thymine, and guanine Adenine and Thymine pair together Cytosine and Guanine pair together

5. Functions of DNA Requires enzymes, proteins, and other chemicals Replication – making copies Protein synthesis – creation of molecules Regulation

6. Replication Nuclear enzymes help break the bonds between the nucleotide bases Unwinds DNA Copying of DNA is required for mitosis and meiosis

7. DNA Replication

8. Protein Synthesis Process by which proteins are produced Proteins is a string of amino acids Code is three nucleotide bases long called triplets 64 possible three-letter combinations but only 20 possible amino acids Some are start and stop amino acids

9. Protein Synthesis: Transcription Copying the DNA message to RNA Message transcribed onto RNA mRNA takes message from the DNA Instead of thymine, RNA uses uracil The triplets transcribed onto RNA are called codons

10. Protein Synthesis: Translation Chemical signals initiate translation Translation is the process of converting the mRNA message into a protein tRNA brings amino acids to the ribosome Create bonds between amino acids Result is a string of amino acids Folding occurs to produce a protein

11. Regulation Error rate of 1 in 10 billion Monitoring system – aligns enzymes with bases Proofreading system – examines the nucleotides Repair system – repairs the segment Repair mechanism – repairs damage from external sources

12. Summary DNA replication, protein synthesis, and regulation are important for everyday life. Without it, life would not exist. DNA is a major part of heredity. Each individual has unique DNA that is received from the parents