2. DeoxyriboNucleic Acid Chemical code containing the information needed for an organism’s growth and function

3. History  1952– Rosalind Franklin used an X- ray crystallography technique to discover that DNA is made of two spiral chains

4. History  1953– James Watson and Francis Crick built on Franklin’s and many other scientists’ research to make the first DNA model... The Double Helix Crick Watson

5. The first DNA model

6. Photo #51

7. DNA Structure It’s like a ladder...the sides are the deoxyribose (sugar) and phosphate backbones and the rungs are the nitrogen bases. Deoxyribose and phosphate group Nitrogen bases

8. Four Nitrogen Bases

9. Stuff to remember... amount of Cytosine = amount of Guanine and amount of Adenine = amount of Thymine So... The bases occur in pairs in DNA!!!

10. Four Nitrogen Bases Adenine TT hymine Guanine Cytosine

12. What is DNA Synthesis ??? The copying of DNA Why copy DNA??? To make new cells

13. Steps to synthesis... 1.An enzyme attaches to the starting point on DNA. 2.The enzyme unzips the DNA to start copying. 3.New nitrogen bases attach to original DNA strands. 4.Two new, complete DNA strands are formed. Let’s see it!!

15. RNA RiboNucleic Acid Carries codes from the nucleus to the ribosome to make proteins Guanine = Cytosine Adenine = ??? Adenine = Uracil 3 types of RNA

16. RNA mRNAMessenger RNA- mRNA –Sends code from nucleus to the ribosome rRNARibosomal RNA- rRNA –Makes up the ribosome tRNATransfer RNA- tRNA –Brings amino acids to the ribosome to make proteins

17. Protein Synthesis Step 1: DNA Transcription Step 2: DNA Translation Step 1: DNA Transcription Step 2: DNA Translation

18. DNA Transcription DNA Transcription Enzyme unzips DNA DNA is synthesized into RNA (mRNA, rRNA, or tRNA) RNA strand releases from the DNA after being copied DNA is zipped back into position by the same enzyme New RNA is transported outside the nucleus of the cell

19. DNA Translation mRNA binds to the rRNA of the ribosome and signals it is ready to be translated One end of tRNA which is 3 nitrogen bases (a codon) that code for a specific amino acid binds with mRNA The mRNA binds several different tRNA units connecting the amino acids to make a protein

20. UGA... More than just a university, It’s also a stop codon!!

21. codon What’s a codon??? It’s the basic unit of genetic code. 3 nitrogen bases = 1 codon Can signal to start or stop a process or can stand for a certain amino acid Examples: UGA, UAA, and UAG are stop codons for the translation process