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DNA: The Blueprint of Life

Discover the wonders of DNA - the molecule that holds the code for all of our genetic information. Learn about its structure, function, and importance in the nucleus of cells. Explore the role of DNA in genetics and how it is replicated and transcribed into RNA. See how scientists like Rosalind Franklin, Watson, and Crick contributed to our understanding of DNA's double helix structure.

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DNA: The Blueprint of Life

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  1. DNA Deoxyribonucleic Acid What is DNA?

  2. Where do we find DNA? In the nucleus What the heck is it? Why is it soooooooooo important? Hint… It’s SUPER IMPORTANT and Mz. C. will be mentioning it over and over and over and… you get the picture! DNA Nucleus Nucleotide Chromosome Nucleic Acid Cell

  3. What do ALL of these organisms have in common? WE all share a universal genetic code: DNA

  4. How do we know what DNA looks like???? • Rosalind Franklin • Chemist… • Used X-Rays and was able to get two photos of crystallized DNA • Watson and Crick used the X-ray data Franklin obtained to figure out the 3-D structure of DNA • Died before she was 38... (due to Cancer caused by Radiation Poisoning)

  5. Watson & Crick • 1953 • Watson & Crick used Rosalind's X-Rays to figure out the structure of DNA… • (Did they give her any credit??? NAH… not until later!)

  6. What they “Announced” • Using Rosalind X-Rays, Watson & Crick determined that phosphates and sugars were on the “outside” of the DNA molecule and nitrogen bases were on the “inside” • They also figured out that DNA is a double helix… • Rosalind figured out that DNA was in a helical shape… but… didn’t get any further details • What’s a helical shape? Let’s talk helicopters… and screws…!

  7. Helix = Spiral Helical spring… Helical screw… Helical staircase… Helic-opter… Helical drill…

  8. DNA

  9. Purpose of DNA • DNA is one of “THE BIG FOUR” Organic Macro-molecules (a Nucleic Acid) • Deoxyribonucleic Acid • Why do we have DNA? • It is our genetic information • The “code” for all of our traits/characteristics! • It gives each cell it’s “instructions”

  10. nitrogen base sugar phosphate Nucleic Acids… • 2 Types: • DNA & RNA • Nucleic Acid is a Polymer • Nucleotides are the monomers • Stores genetic information (genes) • Gives instructions to make proteins • One gene=One protein

  11. 3. 1. 2. 3. 1. O 2. H3 C O O O P C C H2 C O O C N H H C H H C N C H C C H O H O H O What is a Nucleotide? 1. Phosphate Group 2. 5-Carbon Ribose Sugar 3. Nitrogen Base

  12. Three “Similar” Parts • One phosphate group • Bonded to • One sugar (ribose) • To make the “side” of the ladder • One nitrogen base • Makes the “rungs” (steps) of the ladder • There are different Nitrogen bases • DNA & Genes

  13. A G T C Different Nitrogen Bases There are four nitrogen bases in DNA (making up four different nucleotides) Adenine Guanine Thymine Cytosine

  14. Nucleotide Bonding • Nucleotides are bonded together in alternating sugar and phosphate groups • The “Backbone” • This creates a long chain with nitrogen bases sticking off of the side

  15. Making the DNA Ladder • Two chains line up next to each other... • The Nitrogen bases bond together in the center to hold the two chains together like a “zipper” • The bases are held by Hydrogen bonds • The Nitrogen bases only bond in “Complementary Pairs”!

  16. DNA: Double Stranded (Helix) • The Nitrogen bases bond in the center of the “Ladder” • The ladder then “twists” into a helix • The tighter it “twists”, the more “condensed” it becomes • Which means it is more dense and compact

  17. ladder shaped molecule DNA DOUBLE HELIX

  18. A T A A T A T T A A A T T T C C G C G G Erwin Chargaff Chargaff discovered that DNA contains the same amount of adenosine as thymine (A-T) and the same amount of cytosine as guanine (C-G). ALL THUGS CARRY GUNS!

  19. Chargaff’s Base Pair Rules Adenine always bonds with Thymine. A = T T A DNA: All Thugs Carry Guns C G Cytosine always bonds with Guanine. C = G

  20. Pairing DNA Nucleotides What would be the complementary nucleotide pairing for these strands? What is a nucleotide? What is the base pairing rule? P N-b Nucleotide S Rule: A with T C with G

  21. DNA • DNA is the “instruction manual” (the “recipe book”) which tells the cell what proteins to make • But, DNA is “stuck” in the nucleus • It is too large to pass through the nuclear membrane • Which organelle makes proteins? • __________________ • How do the instructions get from the nucleus to the Ribosome???????

  22. RNA – Ribonucleic Acid • Small, Single Stranded COPY of the DNA message • Copy of ONE GENE • RNA is small enough to pass through the nuclear membrane and bring the message to the Ribosome in the cytoplasm • 3 differences from DNA • This allows the organism to recognize that the RNA is NOT the original!

  23. DNA vs. RNA • RNA is Ribonucleic Acid – DNA is Deoxyribonucleic Acid • An Oxygen molecule is missing… making it “Deoxy”… • RNA is a short, single stranded copy • DNA is large, double stranded orginal • RNA contains a different Nucleotide! • Uracil (Not Thymine) • Remember: ALL UNDER- ACHIEVERS CAN'T GRADUATE

  24. Rules for RNA Base Pairing DNA C = G RNA copies the DNA message by pairing with the DNA nucleotides… An “A” is paired with a “U”. “C” and “G” are always paired together… ALL UNDERACHIEVERS CAN’T GRADUATE! C G A = U A U G C T A RNA

  25. What is the function of RNA? Carries the DNA coded message out of the nucleus • RNA copies the information for one gene • One gene = One protein • Brings message to the Ribosome • Ribosome reads the code and makes the correct protein

  26. Types of RNA There is only ONE Type of DNA There are THREE Types of RNA • Messenger RNA (mRNA) • Transfer RNA (tRNA) • Ribosomal RNA (rRNA) • You only need to know two!

  27. Nitrogen Base Phosphate Group Sugar (Ribose) RNA

  28. RNA Codes for Amino Acids The nitrogen bases in RNA code for amino acids • Monomers of Protein A triplet of nitrogen bases codes for one amino acid The triplet is called a “codon” (You NEED to know that!)

  29. DNA vs RNA DNA RNA Nucleic Acids

  30. RNA to Polypeptide • The Scientific Name for Protein is: Polypeptide - Because peptide bonds hold Amino Acids together • The Ribosome reads each “codon” (triplet code) and calls for different Amino Acids to be bonded in the chain • Think “CAN of PEPSI”

  31. Peptide Bond C N

  32. Overall process of protein synthesis translation transcription DNA RNA Protein

  33. Threonine Asparagine Arginine Alanine Proline Proline Glycine Glycine What does a chain of amino acids represent? - a protein! Polypeptide Chain – A Protein

  34. Amino Acid protein Codons One codon codes for one amino acid. EX: ACG = amino acid (threonine) CGC = amino acid (arginine) GGA = amino acid (glycine) Threonine ACG Proline CCG Asparagine AAC Alanine GCC CGC Arginine Proline CCA Glycine GGA Glycine GGC A sequence of amino acids is a protein... A different sequence makes a different protein!

  35. Let’s Try It… • DNA “Complementary Pairs” • Remember: • All Thugs • Carry Guns

  36. Let’s Try It… • RNA “Complementary Pairs” • Remember: • All Underachievers • Can’t Graduate

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