1. Day 4

2. DNA Structure and Replication Chapter 9, pgs. 189-201

3. What is DNA? Deoxyribonucleic Acid Contains genetic information for all living things(acts as blueprint or code). Found in nucleus of Eukaryotic cell. Shape is double helix – looks like twisted ladder or twisted zipper.

4. Polymer made of repeating subunits called nucleotides. Nucleotides have three parts: a simple sugar, a phosphate group, and a nitrogenous base. Backbone or sides of the ladder are the sugar (deoxyribose) and phosphate group. Rungs of the ladder or middle is the bases. Structure

5. In DNA, there are four possible nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). In DNA, there are four possible nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Adenine (A)Guanine (G) Thymine (T) Cytosine (C )  Bases put into 2 categories.  Purines: A and G  Pyrimidines: T and C (both contain Y)

6. Base Pairing Rule Always Together Adenine always pairs with Thymine forms 2 hydrogen bonds with each other Cytosine always pairs with Guanine forms 3 hydrogen bonds with each other

7. Amount of adenine always equal to the amount of thymine. Amount of adenine always equal to the amount of thymine. Amount of guanine always equal to the amount of cytosine. Amount of guanine always equal to the amount of cytosine. Each strand is complementary where sequences on one strand determines sequence on the other. Each strand is complementary where sequences on one strand determines sequence on the other. Complementary base pairs

8. What is the complementary strand? AGTACCGATACGGAATAGC GGTTACATAAATCGGTACC TACCGGAGTAGCATTACTT CATTACCCAATGGACGTTA

10. DNA Replication Process in which DNA makes an identical copy of itself. During Cell division, DNA coils into 46 chromosomes= 23 pairs, one from mom and one from dad. – Chromosomes are DNA and proteins called histones. – Tightly packed DNA and proteins form chromatin – During mitosis, the chromatin condenses to form tightly packed chromosomes

12. Figure 12-10 Chromosome Structure of Eukaryotes Chromosome Supercoils Coils Nucleosome Histones DNA double helix Section 12-2 Go to Section:

13. Section 11.1 Summary – pages 281 - 287 Replication of DNA DNA Replication Step 1. An enzyme, DNA helicase, unzips the DNA molecule. Step 2. Another enzyme, DNA polymerase, adds complementary base pairs to each side of the separated strands producing two identical DNA molecules.

14. Replication occurs in the 5’ prime to 3’ prime direction. DNA polymerase (the enzyme responsible for replication) can only add a new nucleotide onto the 3' end of an existing strand

16. Proofreading DNA A special feature of DNA polymerase is that it checks its work as it copies the strand of DNA. If it mismatches a nucleotide, it backs up and fixes the mistake WHAT HAPPENS IF A MISTAKE IS MADE? – Mutations- Change in the sequence of the DNA

17. Discovery 1949: biochemist Chargaff observed that in DNA, A=T and G=C. 1953: Rosalind Franklin took X-ray of DNA. From X-ray, Watson and Crick developed model of DNA helix.

18. RNA Structure and Protein Synthesis Chapter 10, pg. 208-221

19. What is RNA? Nucleic acid called Ribonucleic Acid Function - Messenger: takes info from nucleus to ribosome Differs from DNA in 3 ways: – Has 5-carbon sugar called ribose (extra Oxygen) – Contains 1 strand of nucleotides – Has nitrogen base that is different Uracel (U) but no thymine (T) – U pairs with A

20. DNA VS RNA- Nucleic acids DNARNA Structure Double Helix Single Strand SugarDeoxyriboseRibose Nitrogen Bases Adenine thymine Cytosine Guanine Adenine Uracil Cytosine Guanine Function Stores and transmits genetic information Messenger: takes info from nucleus to ribosome

21. Purpose of RNA Helps make proteins Traits are determined by proteins Proteins – large molecules made from chains of amino acids – 21 different amino acids found in proteins – some proteins are enzymes and promote chemical reactions and others have important structural functions. protein collagen found in skin, ligaments, tendons, and bones. Hair, hemoglobin, and muscles also contain structural proteins.

22. Protein production A protein is made from the instructions of DNA. This process is called gene expression or protein synthesis. The sequence of nucleotides in each gene determines the string of amino acids in a protein. Protein synthesis consists of two parts: transcription and translation.

23. Protein Synthesis- 2 Processes – 1. Transcription: instructions are transferred from DNA to mRNA. 2.Translation: – instructions are read and amino acids are put together to build the protein.

24. 3-Types of RNA Messenger RNA (mRNA)- Takes info from nucleus to the ribosome. Contains codon Transfer RNA (tRNA) -Brings amino acids with complementary base pairs to the mRna at the ribosome. Contains the anticodon. Ribosomal RNA (rRNA) - Makes up one of the subunits of the ribosomes

25. Transcription Occurs in nucleus. Has 3 main steps. – 1. RNA polymerase, an enzyme, binds to gene’s promoter site (start site) to start process – 2. RNA polymerase unwinds and separates strands of double helix, exposing DNA nucleotides on each side – 3. RNA polymerase adds and links complementary RNA nucleotides as it reads the gene. Follows base pairing rules for DNA replication, except A pairs with U in RNA

26. Transcription cont. RNA polymerase ends process at stop signal at end of gene Not all of the DNA is expressed at once. Usually only one gene or a few genes at a time Exons are the part of the mRNA transcript that are EXPRESSED Introns are regions of unused DNA and removed.

28. Translation mRNA carries the instructions for making a protein to ribosome. – Instructions are read Codons – Codons - 3 nucleotide sequences that code for an amino acid, start signal, or stop signal.

29. Steps of Translation 1.First the mRNA leaves the nucleus, entering the cytoplasm 2.mRNA attaches to the ribosome 3.tRNA carrying an amino acid matches its anticodon to the codon on mRNA 4.Peptide bonds form between the amino acids 5.tRNA is released from the ribosome 6.Process is repeated along length of mRNA until reaches stop codon, ending synthesis of protein.

32. 21 amino acids needed for life Start codon on mRNA always codes AUG and codes for methionine Easy to remember… …we always start school in AUGust!

34. DNA Technology How DNA is Analyzed in today’s world?

35. DNA Technology Uses Since discovery of DNA in 1953, scientists have analyzed the structure of DNA. DNA fingerprinting - test to identify & evaluate the genetic information in living cells. DNA analysis used for: – Crime, forensics, disease, genetics, paternity.

36. The First Step Stage 1: Cells are broken down to release DNA If only a small amount of DNA available, it can be amplified or duplicated using the polymerase chain reaction (PCR)

37. PCR – Polymerase Chain Reaction Makes copies of small fragments of DNA to work with.

38. Stage 2 The DNA is cut into fragments using restriction enzymes. Each restriction enzyme cuts DNA at a specific base sequence.

40. The sections of DNA that are cut out are called restriction fragments. This yields thousands of restriction fragments of all different sizes because the base sequences being cut may be far apart (long fragment) or close together (short fragment).

41. Stages of DNA Profiling Stage 3: Fragments are separated by size using process called gel electrophoresis. DNA fragments injected into wells and electric current is applied along gel.

42. Electrophoresis DNA is negatively charged so it is attracted to the positive end of the gel. DNA is separated on basis of size. The shorter DNA fragments move faster than the longer fragments.

45. Stages of DNA Profiling A radioactive material is added which combines with the DNA fragments to produce a fluorescent image. A photographic copy of the DNA bands is obtained.

46. Stages of DNA Profiling Stage 4: – Patterns or bands are formed in the gel from small and large fragments. – Patterns are unique to each individual and can be used to prove or disprove paternity, guilt or innocence of a crime, determining evolutionary history, etcpaternity

48. Uses of DNA Profiling DNA profiling is used to solve crimes & medical problems

49. Crime Forensic science is the use of scientific knowledge in legal situations. The DNA profile of each individual is highly specific. The chances of two people having exactly the same DNA profile is 30,000 million to 1 (except for identical twins).

50. Biological materials used for DNA profiling Blood Hair Saliva Semen Body tissue cells DNA samples have been obtained from vaginal cells transferred to the outside of a condom during sexual intercourse.

51. DNA Profiling can solve crimes The pattern of the DNA profile is then compared with those of the victim and the suspect. If the profile matches the suspect it provides strong evidence that the suspect was present at the crime scene (NB:it does not prove they committed the crime). If the profile doesn’t match the suspect then that suspect may be eliminated from the enquiry.

52. Whose going to the slammer?

55. Solving Medical Problems DNA profiles can be used to determine whether a particular person is the parent of a child. A childs paternity (father) and maternity(mother) can be determined. This information can be used in Paternity suits Inheritance cases Immigration cases

56. Example: A Paternity Test By comparing the DNA profile of a mother and her child it is possible to identify DNA fragments in the child which are absent from the mother and must therefore have been inherited from the biological father.

57. Whose the Daddy?

58. Practical Uses of DNA Technology 1.Pharmaceuticals 2.Genetically engineered vaccines 3.Increasing crops 4.Crops that don’t need fertilizer 5.Genetically engineered foods

59. GMOs Genetically Modified Organisms

60. Manipulating DNA Genetic Engineering - process of reading and changing DNA sequences in an organism. Reading the Genetic Code – DNA extraction – Cutting and Labeling DNA – Separating DNA – Reading the DNA sequence – Making Copies (PCR – polymerase chain reaction)

61. Transgenic Organisms - organism that contains genes from other organisms Transgenic Bacteria Transgenic Plants Transgenic animals Produce clotting factors insulin HGH Stronger plants More production Pest resistance More production

62. Transforming Animal Cells Can be transformed similar to plants. Some eggs are large enough to physically inject new DNA by hand. Which can “Knock Out” a gene Transgenic organisms contain genes from other organisms. Making onions glow using jellyfish DNA. Using bacteria to make human insulin. Using genetic modification to improve food supply known as GM foods.

63. Cloning – creating an identical copy member of a population of genetically identical organisms produced from a single cell

64. “Dolly, 1 st mammal clone” “Dolly” was an important break through not just because she was a mammal. Frogs were cloned back in 1950’s Why was dolly so special? – Research and answer this question for me.

65. CC the Cloned Cat Embryo that became CC was the only one of 87 embryos produced in this research project that developed into a full- term pregnancy after being transferred to surrogate mothers.pregnancy Born at the College of Veterinary Medicine at Texas A&M University Texas A&M University CC, for "CopyCat" or "Carbon Copy" [1] (born December 22, 2001), is a brown tabby and white domestic shorthair and the first cloned pet. [1]tabbydomestic shorthaircloned pet

66. Human Genome Project 1990-2006 2 goals: 1.Determine the nucleotide sequence of entire human genome 1.3 billion nucleotide pairs, 100,000 genes 2.Map location of every gene on each chromosome

67. Benefits Compare human genome with other species to give information on: 1.Organization of genome 2.How gene expression controlled 3.Control of cell growth and differentiation. 4.How evolution occurs