#2 donohue dna, protein synthesis and biotech


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  • DNA fingerprinting info (explain to students)The chemical structure of everyone's DNA is the same. Only difference between people (or any animal) is the order of the base pairs. There are so many millions of base pairs in each person's DNA that every person has a different sequence.Using these sequences, every person could be identified solely by the sequence of their base pairs. However, because there are so many millions of base pairs, the task would be very time-consuming. DNA finger printing uses the short, repeating segments of human DNA for comparisonThese patterns do not, however, give an individual "fingerprint," but they are able to determine:If samples are from the same person, related people, or non-related people. Scientists use a small number of sequences of DNA that are known to vary among individuals a great deal, and analyze those to get a certain probability of a match.
  • Explain what a DNA finger print is…click on interactive activity
  • #2 donohue dna, protein synthesis and biotech

    1. 1. From Peas and fruit flies to humans…
    2. 2. What is a genome??? All the genetic information (genes) that make up an organism
    3. 3. What makes ushuman? Analyze human chromosome… Karotype  Picture of all the chromosomes in an organism  Autosomes ○ CHROMOSOMES 1-44 (pairs 1- 22) ○ Autosomal chromsomes  Sex chromosomes ○ Determine a person’s sex (male XY or female XX) ○ Chromosome 45 and 46 (set 23)
    4. 4. DNAStructureAcidDeoxyribonucleic DNA is a polymer made up of many monomers called nucleotides Nucleotide contains:  5-carbon sugar called deoxyribose  RNA contains RIBOSE sugar instead  Phosphate group  One Nitrogenous base (there are 4 types)
    5. 5. What are these Nitrogenous bases??? Make up the “steps” of the DNA ladder  One Step= A Purine + A Pyrimidine Purines  Double ring structure  Adenine  Guanine Pyrimidines  Single-ring structure  Cytosine  Thymine (in DNA only)  Uracil (in RNA only)
    6. 6. Nucleic Acids RNA  DNA  Single Strand  Double strand  Ribose sugar  Deoxyribose sugar  A=U  A=T  G=C  G=C  Uracil is the nitrogenous base used instead of THYMINE
    7. 7. DNA Review The 2 Fates of DNA Protein Synthesis DNA Replication (when cell is doing is (if cell enters cell normal job-in G1 division…S-phase) phase of cell cycle)
    8. 8. DNA Facts All living things have DNA  Prokaryotes-DNA in cytoplasm, simple ○ Contain extra DNA called PLASMIDS  Eukaryotes-DNA in nucleus, complex DNA codes for the same 20 amino acids in ALL living things  It is the UNIVERSAL code...all organisms have the same A,T,G and C bases and the same 20 a.a., just arranged differently
    9. 9. 5The DNA backbone PO4  Putting the DNA backbone together base 5 CH2  refer to the 3 and 5 ends O 4 1 of the DNA C 3 ○ the last trailing carbon O 2 –O P O Sounds trivial, but… O base this will be 5 CH2 IMPORTANT!! O 4 1 3 2 OH 3
    10. 10. Anti-parallel strands Nucleotides in DNA backbone are bonded from phosphate to sugar 5 3 between 3 & 5 carbons  DNA molecule has “direction”  complementary strand runs in opposite direction 3 5
    11. 11. Bonding in DNA hydrogen bonds 5 3 3 5….strong or weak bonds?How do the bonds fit the mechanism for copying DNA?
    12. 12. Base pairing in DNA  Purines  adenine (A)  guanine (G)  Pyrimidines  thymine (T)  cytosine (C)  Pairing  A:T ○ 2 bonds C:G ○ 3 bonds
    13. 13. Copying DNA Replication of DNA  base pairing allows each strand to serve as a template for a new strand  new strand is 1/2 parent template & 1/2 new DNA ○ semi-conservative copy process
    14. 14. Let’s meet the team…DNA Replication  Large team of enzymes coordinates replication
    15. 15. Important Enzymes DNA Helicase  Unzips original DNA strand DNA Polymerase  Adds nucleotides to the unzipped sides DNA Ligase  Attaches/glues DNA fragments together on one of the new copies
    16. 16. How does DNA replicate itself? Template mechanism  What is a template???  Like the negative of a photograph DNA Replication  Process of copying the DNA molecule ○ What phase of the CELL CYCLE?  S-phase….  2 strands of double helix separate (Unzips)  Each strand acts as a negative for making the new complementary strand  Nucleotides line up one by one following base pairing rules  Enzymes (DNA Polymerase and DNA Ligase) link nucleotides together to form 2 new DNA strands called the daughter strands
    17. 17. Fate #2: Protein Synthesis You already know about this…central dogma of Biology Just need to know your key players…
    18. 18. The Protein Synthesis Team DNA mRNA tRNA rRNA Codons Anticodons Amino acids Proteins Introns Exons
    19. 19.  DNAmRNAprotein DNA TRANSCRIBES to mRNA  Process is called transcription mRNA TRANSLATES to proteins  Process is called translation  mRNA actually makes amino acids, which come together to make proteins
    20. 20. DNAmRNAamino acids/polypeptide chain(Proteins) DNA codes for an RNA strand The every 3 bases on the RNA strand code for a specific amino acid  CODON: three sequential bases that code for a specific a.a. (20 a.a. total)  Amino acid are strung together to make a protein (primary structure) Change DNA will change RNA which will change amino acids, which change protein
    21. 21.  Transcription DNAmRNAProtein  Different form of the same message  DNA makes single stranded RNA (U replaces T)  RNA leaves nucleus Translation  Translate from nucleic acid language to amino acid language  Uses codons, 3-base “word” that codes for specific a.a. ○ “code” for an amino acid  Several codons make a “sentence” that translates to a polypeptide (protein)
    22. 22. Start StopCodons Codons AUG  UAA  UGA  UAG
    23. 23. Three Types of RNA  mRNA  tRNA  rRNA
    24. 24. Three Types of RNA… #1 mRNA (messanger RNA)  RNA transcribed from DNA template  Modified in nucleus before if exits ○ RNA splicing: process in which Introns are removed and exons re joined together to make a continuous coding mRNA molecule  Introns ○ Internal non-coding regions of DNA and mRNA ○ Space fillers/jibberish ○ They are cut out of mRNA before it is allowed to leave the nucleus ○ Process is called RNA splicing (processing)  Exons (MOST important part of DNA) ○ Coding region of DNA and mRNA that will be translated (Expressed) ○ VERY important part of mRNA…it is carrying the message from DNA (def can’t cut this out)
    25. 25. Three Types of RNA…#2 tRNA (transfer RNA)  The interpreter  Translate 3-letter base codes into amino acids  Carries anti-codon on one end (three letters opposite of what is on mRNA)  Carries amino acid on other end  Anti-codon recognizes codon and attaches
    26. 26. Three Types of RNA…#3 rRNA (ribosomal RNA)  Found in ribosome  Ribosome composed of 2 subunits: ○ Small subunit for mRNA to attach ○ Large Subunit for two tRNAs to attach  “P” site: holds the tRNA carrying the growing polypeptide chain  “A” site: holds the tRNA that is carrying the next a.a. to be added to the chain  When stop codon (UAA, UAG, UGA) is reached, translation ends and polypeptide is released
    27. 27. Mutations Occur when there is an error in DNA replication Def: Change in genetic material Mutagens  Physical or chemical agents that cause mutations ○ Ex: high energy radiation (x-ray or UV) ○ Ex. Chemicals (that are similar to DNA but cause incorrect base pairing)
    28. 28.  Mutation  Any change in the nucleotide sequence of DNA  Large or small 2 Main types  Point Mutation ○ Base Substitutions  Frameshift Mutation  Insertions or deletions
    29. 29. Base Substitution Replacement of one base or nucleotide with another Usually do not change amino acid Sometimes causes a change in the protein made Silent Mutation  When a substitution does not cause a change in the protein expressed by a gene  Remember some codons represent the same amino acid  Example: GAA and GAG both code for Glu
    30. 30.  Point Mutation A point mutation is a simple change in one base of the gene sequence. This is equivalent to changing one letter in a sentence, such as this example, where we change the c in cat to an h: Original: The fat cat ate the wee rat. Point Mutation: The fat hat ate the wee rat.
    31. 31. Insertion or Deletion Nucleotide is removed or added More disastrous mRNA is read as triplet codes  Adding/removing bases changes these three letter codes  Codons downstream from insertion/deletion will be regrouped and probably code for a non- working protein Result: FRAMESHIFT MUTATION  Shift the “reading” frame of the genetic message
    32. 32. Frameshift mutation Original: The fat cat ate the wee rat. Frame Shift: The fat caa tet hew eer at.
    33. 33. Chromosomal Mutations Involve changes in the number or structure of the chromosome
    34. 34. Chromosomal Disorders Mechanics of meiosis (where we separate chromosomes) is usually pretty good But nobody’s perfect…mistakes happen…. Most common problem…  Nondisjunction: when homologous chromosomes fail to separate properly  Literally means “not coming apart”  If this occurs, ABNORMAL #s of chromosomes may find their way into gametes and a disorder of chromosome number may result
    35. 35. Nondisjunction If one of the gametes with an ABNORMAL # ends up getting fertilized, MAJOR problems!!!  Trisomy: “three bodies” ○ Occurs when an autosomal chromosome fails to separate during meiosis  When do chrm separate? - Anaphase I and Anaphase 2 ○ One gamete ends up with an extra copy of a chromosome and then the fertilized zygote ends up with 3 copies of a chrm instead of 2 ○ Example: Downs Syndrome
    36. 36. Chromosomal Mutations May change location of genes on chromosome Include:  Deletions: loss of part of chromosome  Duplications: produce extra copies of parts of chromosome  Inversions: reverse direction of chromosome  Translocation: when one chromosome breaks off and attaches to another
    37. 37. Mutations NOT always harmful Some alter a protein in a beneficial way that may help species in a specific environment If mutation is present in organisms gametes, it may be passed off to off- spring Mutations are the ULTIMATE source for GENETIC DIVERSITY!!!
    38. 38. What is biotechnology?  Here are some hints…
    39. 39. Biotechnology Manipulation of living organisms or their parts to produce useful products Main use is to improve human health and food production  Seedless fruits  Make insulin
    40. 40. Genetic engineering The transfer of genes or pieces of DNA from one organism into another organism  New DNA is a combination of pieces from two different organisms…called recombinant DNA Used to introduce new characteristics into organisms and populations Gentically Modified Organisms GMOs
    41. 41. How to make recombinantDNA Use DNA from complex organism (human) and transfer to a simple organism (bacteria) Uses a PLASMID  Small circular DNA in bacteria  It is called a VECTOR when used in genetic engineering
    42. 42. Genetic Engineering Positive/benefits  Negatives/Cons  Make medicine like  Unknown long term insulin and vaccines effects if ingested by plentiful and humans inexpensive  Harm native, natural  Improves crop plants species like corn and rice  Cross pollination ○ Grow faster and between GMOs and stronger wild plants resulting in ○ Resist disease and unwanted hybrids insects (mockingjays!) ○ Genes can be added  ***Decreases genetic to add more vitamins variation to plants
    43. 43.  The chemical structure of everyonesDNA Fingerprinting DNA is the same.  Only difference is order of base pairs  Too many bases to analyze every Not like the single one, so scientists analyze groups /segments of bases fingerprint on your  These patterns do not, however, give an hand individual "fingerprint," but they are able to determine: Used to determine  If samples are from the same person, the paternity of a related people, or non-related people. child and in  There are a few small fragments in humans that scientists KNOW vary forensics (the CSI greatly from individual to individual stuff you see on TV)  They analyze those segments and get a certain probability of a match
    44. 44. Lets Try It Out!CLICK ME!!!
    45. 45. Test Your DNA knowledge DNA Practice EOC exam questions Answers to DNA questions