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Polymers

Learn about the structure and function of DNA, including the history of its discovery by scientists Watson, Crick, Wilkins, and Franklin. Explore the importance of nucleotides, bases, and hydrogen bonds in DNA replication, and how mutations can impact genetic traits.

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Polymers

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  1. Polymers DNA Structure and Function

  2. History of DNA • Scientists were aware that DNA had a sugar phosphate background and had bases A, T, G and C but were not sure about the actual shape of DNA. • Wilkins and Franklin used X-ray crystallography to create images of DNA’s structure. • Watson discovered that the base pairs A to T were exactly as long as G to C. Causing each rung to be of equal length

  3. Founders • Now that they had the shape – helical or twisted ladder – and the base pairing rule, they could share with the scientific community the shape of DNA. NOBEL PRIZE awarded to Watson and Crick shared with Wilkins and Franklin for discovering the shape of DNA.

  4. Nucleic acids • DNA – Deoxyribonucleic Acid – a simple polymer • the “molecule of heredity.” DNA Animation http://www.youtube.com/watch?v=l-hrLs03KjY&feature=related

  5. Job of DNA • Stores information on how to make proteins; the building–blocks of living organisms Hydrogen Bonds phosphate Sugar SHAPE – Double helix

  6. What is a Monomer • the simple building blocks used to hook together to build long, complex polymers ex. Keratin (protein in hair), Nylon, plastics,…

  7. O CH3 H N O O O OH P O N CH2 O C C OH C C OH OH What is a Nucleotide? The monomers that builds up the DNA polymers What are the components found in nucleotides? • Sugar • Phosphates • Bases A Nucleotide

  8. HOCH2 HOCH2 OH OH O O C C C C C C C C H H OH OH OH Sugar Phosphate C6H12O6 Found on DNA Sides of the ladder Backbone of DNA Ribose Deoxyribose DNA is found in the Nucleus

  9. NH2 OH OH N N N N H2N N N HO HO N N H O CH3 H N O N H NH2 N N N N H Types of Bases Adenine Uracil – only in RNA Guanine Thymine Cytosine

  10. Purines and Pyrimidines Purines- double ringed Pyrimidines – single ringed

  11. Which Bases Pair Together A = T C = G Why do they pair together? Hydrogen bonds A = T has two bonds G = C has three bonds

  12. Anti-parallel-What does it mean?

  13. What are Genes? Long stretches of DNA that are “recipes” for how to build a specific protein. • For example: the gene for Kertain is a stretch of DNA with instructions for building a Keratin molecule

  14. DNA GENE PROTEIN TRAIT Summary Flow Chart

  15. How are genes, proteins, traits, DNA and chromosomes related? • traits are the result of proteins • Proteins are determined by a stretch of DNA called a gene. • Genes are stretches of DNA on a chromosome. • DNA codes for the proteins that make up traits

  16. What could happen if genes had the wrong sequence of nucleotides? • Incorrect proteins could be made. This could lead to disease, spontaneous abortion, cancer or death. Called a Mutation

  17. Mitosis G2 Cell Cycle G1 S • When does DNA remake itself? • Interphase • 3 parts to Interphase • G1 – cell carries out normal functions • S – DNA is copied • G2 – Cell carries out normal functions DNA Synthesis

  18. What must be present for DNA to remake itself? • Original • Ink and paper • Photocopier Original DNA Nucleotide DNA Polymerase

  19. Original Strand The original strand is used as a template Example:

  20. A nucleotide is the sugar, phosphate and base. • Where do the “free” nucleotides come from? • From the food that we eat • Adenine, Thymine, Cytosine, Guanine

  21. What is an enzyme? • An enzyme is a protein • “Cellular Machine” that can build up or tear apart molecules.

  22. DNA replication wrap up • http://www.youtube.com/watch?v=hfZ8o9D1tus • Template (original) Strand – original strand used to tell what nucleotide to add • b. Newly Synthesized (copy) Strand – just being built, a copy of the original strand

  23. What happens during DNA replication? a. - DNA unzips • Helicase unwinds DNA double helix; breaks hydrogen bonds

  24. b. - DNA polymerase attaches to DNA

  25. c. DNA polymerase copies DNA • Free nucleotides find their compliments on each side of the DNA strand

  26. New bases keep attaching until two identical molecules of DNA are created. • This is called semi-conservative replication. THE RESULT: 2 new DNA molecules, each is ½ old strand, ½ new strand Mitosis then follows where each cell gets copy 1 2

  27. A T T A G C A T C G A – T – G – A – C – T A C T G A T G A C - T - A - C - T - G A – T T – A G – C A – T C - G • DNA unzips • Hydrogen bonds broken • DNA is copied • Free nucleotides attached

  28. A T T A G C A T C G A – T – G – A – C – T A C T G A T G A C - T - A - C - T - G A – T T – A G – C A – T C - G Template Strand Template Strand • Old DNA strand

  29. A T T A G C A T C G A – T – G – A – C – T A C T G A T G A C - T - A - C - T - G A – T T – A G – C A – T C - G Copy Strands • New DNA Strand

  30. Reads in an anti-parallel direction when bringing in free nucleotides EX:

  31. http://www.dnalc.org/view/15509-DNA-replication-animation-3D-animation-with-basic-narration.htmlhttp://www.dnalc.org/view/15509-DNA-replication-animation-3D-animation-with-basic-narration.html Video http://www.youtube.com/watch?v=zdDkiRw1PdU&feature=related Song: http://www.youtube.com/watch?v=dIZpb93NYlw&feature=related

  32. ANIMATIONS http://www.contexo.info/DNA_Basics/DNA%20Replication.htm http://www.teachersdomain.org/sci/life/gen/mechdna/index.html

  33. Proteins • Subunits of life Monomers – Amino Acids Polymers – many A.A. joined together to form a polypeptide chain

  34. To Recognize • Amino group NH2 or NH (circle in green) • Carboxyl COOH or CO (circle in red) These are the “side chains” or R groups – makes each amino acid different from one another

  35. Amino Acid Amino Acid Amino Acid Amino Acid Amino Acid Amino Acid Amino Acid Proteins – long chain of amino acids bonded together • Peptide bond (Circle in figure below) Peptide Bond

  36. Organisms build proteins from 20 amino acids • Flip and look at the page with our 20 amino acids. • Don’t need to memorize these, but notice……ALL have an NH2 and a COOH group.

  37. Why are protein important? • Enzymes – speed up biological reactions • Antibodies – immune system • Channels – allow ions through cell membrane by creating channels

  38. Types of Proteins Enzymatic (speed up/control chemical reactions) • Catalase – located in plants, animals and aerobic bacteria to break down hydrogen peroxide (otherwise harmful, toxic) into water and oxygen H2O2 H2O + O2 H2O2 poison builds up as we digest food • In the liver H2O2 is changed to water and oxygen by Catalase

  39. Rhodopsin – a protein in the membrane in the photoreceptor cell in the retina in the eye. This part changes shape when light hits it and leads to a nerve impulse to being transmitted to the brain

  40. Structural (our building blocks) actin and myosin work together to help the muscle cells relax and contract

  41. Oxygen Carriers – Hemoglobin is two proteins (alpha and beta) are in red blood cells that “stick together” They carry oxygen

  42. Hormones (send signals) – Insulin- binds and changes shape of receptor to form a tunnel to allow entry of molecules such as glucose into the cells.

  43. Now that you understand: • What determines the role or function of a protein? Shape • What determines the shape of a protein? Function

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