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DNA The Blue Prints of Life!

What do you think is the purpose of DNA ...why does it exist at all? Is DNA found in all creatures? How different is DNA among different creatures? A dog? A banana? A bacterium?. DNA The Blue Prints of Life!.

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DNA The Blue Prints of Life!

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  1. What do you think is the purpose of DNA ...why does it exist at all? Is DNA found in all creatures?How different is DNA among different creatures? A dog? A banana? A bacterium? DNA The Blue Prints of Life!

  2. If the total DNA in one person were laid in a straight line, it would stretch to the sun and back over 600 times (it's 93 million miles from here to the sun).

  3. You could fit one million threads of DNA across the period at the end of a sentence.

  4. Modern Humans have about 1 – 4 % Neanderthal DNA. The difference between your DNA and the person next to you is less than 0.1%. You share about 96% of your DNA with a Chimpanzee, our closest relative on planet Earth. You share about 60% of your DNA with a Banana.

  5. Chapter 12 DNA and RNA

  6. What is DNA? • DNA (De-oxy-ribo-nucleic Acid) is the nucleic acid that stores the genetic code. What is a Genetic Code? • Genetic Codes are programs of the cell. In other words how cells store information they pass from one generation to the next.

  7. WHAT IS DNA MADE OF? • DNA is a polymer (Large Molecule) formed from units called nucleotides. • A nucleotide is made up of three parts: • Nitrogen base • Deoxyribose (5 carbon sugar) • Phosphate group

  8. NITROGEN BASES • There are 4 different nitrogen bases: • Adenine(A) and Guanine(G) which are the purines • Cytosine(C) and Thymine(T) which are the pyrimidines

  9. BASE PAIRING RULES • Erwin Chargaff discovered the base pair ruling that in DNA: • Adenine (A) pairs with Thymine (T) by 2 hydrogen bonds • Cytosine (C) pairs with Guanine (G) by 3 hydrogen bonds REMEMBER • AT and GC • OR ELSE!!!!!

  10. Testing Your SkillCan you write the corresponding Nitrogen Base? • GAC TAT ATT GAC ATT GAG CCC TTA • ATA GAG CAC GCA TAT CCG AGT TAT Do you understand how to match up the bases??? IF NOT ASK FOR HELP NOW!!!

  11. STRUCTURE OF DNA: • Is called a double helix (resembles a twisted ladder): has 2 strands

  12. Watson and Crick • Made the first model of the DNA ladder called the Double Helixin 1953. • They used X-ray crystalography pictures created by Rosalind Franklin and Chargaff’s rule to develop their ladder. • They won the nobel prize in 1962 for their accomplishments.

  13. Rosalind Franklin also played a major role in the ladder’s discovery because Watson and Crick used her photos of the DNA ladder to figure out and assemble the model.(Unfortunately she died 4 years before the nobel prize was awarded at the age of 37 of ovarian cancer. Her contributions were made known later after the award was given. According to Nobel Prize Rules, the individual must be alive in order to receive the award ) ROSALIND FRANKLIN

  14. Scientists • Fredrick Griffith (microbiology research with nucleic acids) • Oswald Avery (colleague that completed/supported Griffith’s work) • Alfred Hershey and Martha Chase (proved that DNA and not protein is the genetic material of life) • Erwin Chargaff (A-T, G-C) • Rosalind Franklin (x-ray pics-DNA) • Francis Crick and James Watson (double helix model)

  15. Rosalind Franklin Born: London, England, July 25, 1920 Died: London, England, April 16, 1958 Pioneer Molecular Biologist There is probably no other woman scientist with as much controversy surrounding her life and work as Rosalind Franklin. Franklin was responsible for much of the research and discovery work that led to the understanding of the structure of deoxyribonucleic acid, DNA.

  16. DNA Replication (synthesis) DNA replicationis an important process because as cell divide, it is critical that the two daughter cell are identical to the original cell. Now we will look at how DNA replication take place.

  17. Each strand (side) of DNA serves as a template for a new strand of DNA Steps of replication: Enzymes unzip DNA breaking hydrogen bonds between bases. The two strands unwind. Each DNA strand serves as a template for complementary bases. Example: TEMPLATE DNA: TAC-GTT NEW DNA: ATG-CAA DNA replicates itself exactly so that each new cell will have an identical copy of the original DNA ladder. Process of DNA Replication

  18. DNA REPLICATION VIDEO

  19. REPLICATION VIDEO (ADVANCED)

  20. RNA There are 3 different types: mRNA tRNA rRNA

  21. mRNA • mRNA is the nucleic acid that acts as a messenger between DNA and ribosomes and carries the genetic code for making protein from amino acids.

  22. mRNA Just like DNA, RNA is made of Nucleotides: A, U, C, G. Notice, RNA does not contain thyamine (T) as a base, but instead has uracil (U). So in RNA its AU and CG

  23. PROTEIN SYNTHESIS Why make protein? Proteins are needed for cell structure and movement, makes enzymes and nucleotides.

  24. Transcription is the process in which a molecule of DNA is copied into a complementary strand of RNA. DNA is in the nucleus and can’t leave, so a messenger RNA-(mRNA) must bring the genetic information from the nucleus to the ribosomesin the cytoplasm TRANSCRIPTION

  25. RNA polymerase attaches to DNA and moves along it unwinding the two strands RNA nucleotides match up with the bases of DNA Ex: DNA TGCACGCA mRNAACGUGCGU Steps in Transcription

  26. CODONS • Codon- is a 3 letter word composed of 3 nucleotides on mRNA. • Each codon codes for a particular amino acid while chains of amino acids form proteins. • There are 64 different codons; there can be more than 1 codon for each amino acid. • There are start and stop codons. EXAMPLES OF CODONS AUG-CCC-GAA-GGG-UAA

  27. CAN YOU IDENTIFY THE CODONS IN THE PROBLEMS BELOW? • AUGCCCAUAGACUAG • AUGGACCGGCUUUAA YOUR TEACHER WILL TEACH YOU HOW TO USE THE CODON TO IDENTIFY THE AMINO ACID

  28. PROTEIN SYNTHESIS VIDEO

  29. STILL CONFUSED? • Imagine that you are a mechanic. The repair manual that you use is the DNA ladder. • If you wanted to copy the instructions to install a radio in your car, would you copy the entire repair manual? (RAISE YOUR HAND TO ANSWER) • NO!!! You would only copy the portion pertaining to installing the radio. That is what transcription does.

  30. CONTINUED • Enzymes open the DNA ladder and the needed portion is copied in the form of mRNA. • Why is it called mRNA? It carries the message or instructions on how to assemble something. • What’s next? This message is carried from the nucleus to a ribosome which is located outside of the nucleus. (HINT: M=Messenger)

  31. translation • is the process of building a protein molecule according to code in mRNA.

  32. Translation cont. • During the process, transfer RNA (tRNA) carries amino acids to ribosomes where the amino acids are joined to form the protein. (**ribosomes are the place where protein are made)

  33. Translations cont. • Steps of translation: 1. tRNA bind to the mRNA. 2. a “start” codon start the protein synthesis. 3. tRNA contains 3 complementary nucleotides to the mRNA called the anticodon; once it matches it leaves behind amino acid and next codon is read.

  34. Translation cont. • More tRNA molecules will come together to create the _____________. • Once a “stop” codon is read, the new polypeptide chain is released as a new protein.

  35. Translation Video

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