2. NOTE: This presentation was not made for public use. Please do not use this presentation without my permission and the permission of each of the authors of the photographs, quotes, and other materials that they contain. Thank you, Vicki Hughes

3. What is DNA? DNA = Deoxyribonucleic Acid Made of four (4) different nucleotides. (Colors don’t matter.)

4. What is DNA? DNA is a molecule that carries the information our cells use to make proteins that determine our traits. DNA’s structure is like a twisted ladder. We call this shape a DOUBLE HELIX. What do you notice about this ladder? The yellow always links with the green and the pink always links with the blue!

5. What is DNA? Chromosome = folded up DNA Gene = a section of DNA that codes for a specific trait Allele = the particular version of the trait Example: On a chromosome, there is a gene for eye color. The allele determines that this eye’s color will be blue. Chromosome Gene Allele Gene

6. Strands “unzip” at the weak bonds between bases DNA Replication Old DNA

7. DNA Replication Old DNA Enzyme – DNA polymerase – adds new bases Old DNA Free floating DNA bases in nucleus

8. DNA Replication Get 2 exact copies of DNA to split between the two new cells. Old DNA New DNA Old DNA The copies are semi-conservative = ½ old DNA and ½ new DNA.

9.  deoxyribose sugar  nitrogen bases  G, C, A, T  T = thymine  T : A  C : G  double stranded  ribose sugar  nitrogen bases  G, C, A, U  U = uracil  U : A  C : G  single stranded D NA R NA Structure and Role of RNA

10. DNA is TOO BIG! RNA is half the size of DNA because it is only a single helix. It carries the info and so is called “messenger RNA” (mRNA). DNA gives its information to mRNA (messenger RNA) to carry out of the nucleus. TOO BIG! Just right. Need a messenger to carry the info from DNA to the ribosomes in the cytoplasm. to mRNA Transcription

11.  Double stranded DNA unzips AGGGGGGTTACACTTTTTCCCCAA TRANSCRIPTION

12. RNA nucleotides fill in matching the DNA but using U- A and C-G. U AGGGGCTTTTTCCCCAA U U U U U G G A A A CC C C C C C G G G G A A A A A TRANSCRIPTION GGTTACA

13.  DNA  instructions remain in nucleus  mRNA  has the instructions for building proteins from DNA  Proteins  built as chains of amino acids  What reads mRNA?  need a mRNA reader  rRNA in ribosomes reads mRNA! UCCCCCCAAUGUGAAAAAGGGGUU

14. cytoplasm aa mRNA DNA nucleus Protein Trait UCCCCCCAAUGUGAAAAAGGGGUU rRNA ribosome mRNA leaves nucleus through nuclear pores rRNA inside the ribosomes read the mRNA Transcription CELL aa Translation

15. mRNA From gene to protein DNA nucleus Protein Trait UCCCCCCAAUGUGAAAAAGGGGUU ribosome Transcription cytoplasm aa Translation aa tRNA tRNA (transfer RNA) carries the correct amino acid (based on the mRNAcode) to the ribosome.

16. TACGCACATTTACGTACGCGG DNA AUGCGUGUAAAUGCAUGCGCC mRNA Met Arg Val Asn Ala Cys Ala protein How can you code for 20 amino acids with only 4 nucleotide bases (A,U,G,C)?

17. AUGCGUGUAAAUGCAUGCGCC TACGCACATTTACGTACGCGG DNA AUGCGUGUAAAUGCAUGCGCC mRNA Met Arg Val Asn Ala Cys Ala Amino acid ? ribosome Codon = set of 3 bases

18. The code is UNIVERSAL! Since all living organisms… – use the same DNA – use the same code book – read their genes the same way AUG ACT p177

19. TACGCACATTTACGTACGCGG DNA AUGCGUGUAAAUGCAUGCGCC mRNA tRNA Pro Ala Met Val Leu tRNA Met Transcription and Translation Builder http://learn.genetics.utah.edu/content/begin/dna/transcribe/ tRNA

20. You Transcribe and Translate a Gene! http://learn.genetics.utah.edu/content/begin/dna/ Step Through Translation http://bcs.whfreeman.com/thelifewire/content/chp12/1202003.html DNA Translation Real Time and Interactive http://www.dnai.org/a/index.html http://www.dnai.org/a/index.html DNA PRACTICE! Gene to Protein (transc., transl., splicing, etc.) http://www.yourgenome.org/downloads/animations.shtml http://www.yourgenome.org/downloads/animations.shtml Transcription in RealTime http://www.youtube.com/watch?v=D3fOXt4MrOMhttp://www.youtube.com/watch?v=D3fOXt4MrOM

21. ANY QUESTIONS?