2. Nucleic acids DNA

3. LOCATION OF DNA  Controls protein synthesis  Carries hereditary characteristics  Controls protein synthesis  Carries hereditary characteristics

4. DNA –Position in the cell Nucleus DNA double helix Chromosomes

6. A.Rosalind Franklin and Maurice Wilkins - X-ray photo of DNA.(1952) B.Watson and Crick - described the DNA molecule from Franklin’s X-ray. (1953) C. Watson crick and Wilkins – received Nobel price (1962). Franklin passed away Complete activity textbook pages 16-17

8. DNA Structure DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix. A molecule of DNA is made up of millions of tiny subunits called Nucleotides. Each nucleotide consists of: 1.Phosphate group 2.Pentose sugar 3.Nitrogenous base

9. Nucleotides Phosphate Pentose Sugar Nitrogenous Base

10. Nucleotides The phosphate and sugar form the backbone of the DNA molecule, whereas the bases form the “rungs”. There are four types of nitrogenous bases.

11. Nucleotides A Adenine T Thymine G Guanine C Cytosine

12. Remember DNA T – A G - C

14. It's hard to believe that an alphabet with only four letters can make something as wonderful and complex as a person

15. Nucleotides Each base will only bond with one other specific base. Adenine (A) Thymine (T) Cytosine (C) Guanine (G) Form a base pair.

16. DNA Structure Because of this complementary base pairing, the order of the bases in one strand determines the order of the bases in the other strand.

17. G G A T T A A C T G C A T C

18. DNA Structure To crack the genetic code found in DNA we need to look at the sequence of bases. The bases are arranged in triplets called codons. A G G - C T C - A A G - T C C - T A G T C C - G A G - T T C - A G G - A T C

19. A gene is a section of DNA that codes for a protein. Each unique gene has a unique sequence of bases. This unique sequence of bases will code for the production of a unique protein. It is these proteins and combination of proteins that give us a unique phenotype.

20. THE ROLE OF DNA (pg 23) PROTEIN SYNTHESIS- DNA has the code to make all proteins PASSING ON OF HEREDITARY MATERIAL- Passed on from parent to offspring. REPLICATION- DNA can make a copy of itself for cell division. CARRYS GENETIC INSTRUCTIONS- Has instructions to make all components of the cell. MAINTAINS STRUCTURE AND REGULATION- large sections of DNA are non-coding and they maintain structure of chromosomes and regulate the functions of genes.

21. HOMEWORK PG 20 EX 1.

22. Process of making a new DNA molecule from an existing DNA molecule that is identical to the original So that genetic code is passed on to each new daughter cell formed during cell division During interphase

23. DNA REPLICATION PROCESS UNWIND UNZIP COMPLEMENTARY PAIRING REZIP REWIND CONTROLLED BY ENZYMES

25. DNA Replication Unzip into two single strands

26. New bases attached themselves in the correct place of each strand Free nucleotides in nucleoplasm

27. Two identical strands are formed Each strand now becomes a double helix. Strand 1 Strand 2

28. 1. Identify the above molecule. 2. Give labels for parts numbered 1to 5 3. Describe how the above molecule replicates itself. 4. What is it significance that this molecule can replicate itself? Questions on the DNA Molecule 1 2 3 4 5 G T

30. H bonds break Two strands seperate

31. Sugar phosphate backbone is made by joining the adjcent nucleotides ( DNA polymarase enzyme ( ) ) Nucleotides with Complementary bases are assembled alongside each strands

32. Two identical DNA molecules are formed

33. HOMEWORK pg 20 Ex 1 ANSWERS 1 A Deoxyribonucleic acid B Double helix C Adenine, Thymine, Cytosine and Guanine D Weak hydrogen E Pyrimidines 2. Nucleotides join with matching bases e.g. A-T and C-G 3. It is made of small molecules called nucleotides 4. These are complimentary bases for each C there will be a G attached on the other strand of DNA

34. DNA Profiling Each PERSON’S DNA profile is unique!

35. What is DNA Profiling? A technique used by scientists to distinguish between individuals of the same species using only samples of their DNA

36. Where do we get DNA

37. DNA profiling Technique used to identify sequence of bases The nucleotides are separated from each other in the order that they are found in strand of DNA. Nucleotides appear as dark bands The sequence in this segment of DNA reads CTT- AGT Use as DNA fingerprint Unique for every person

38. 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.

39. 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

40. DNA fingerprinting is often used by the police in identifying the suspect of a crime. A useful but controversial method A sample of a suspect’s bodily fluid or tissue is to be compared with a sample found at the scene of a crime. The pattern of lines represents a person’s specific genetic make-up. DNA fingerprinting use in 11/9 disaster to identify victims DNA Fingerprinting

41. 1 2 3 4 5 6 7 8 9 X Problem 1: X is a DNA sample found at the scene of a murder. 9 suspects were requested to provide DNA samples. Which person is likely to be the murderer? Could this be disputed?

42. HOMEWORK PG 28 CASE STUDY 2

43. ANSWERS CASE STUDY 2 1 From Chantal T 2 Possibly as a result of a tussle with the killer. 3. The victim 4. Chantal T 5. The sample might be from the victim themselves and not the killer. 6. No, we can confirm that her skin was under the victims nails, not that she committed the murder.

44. Diabetics need insulin to live Diabetes use insulin from pigs and cattle. This is not the same as human insulin and sometimes produces side effects. With genetic engineering, bacteria are used to produce some human insulin Bacterial DNA - Manufacturing of insulin

46. 1. A ring of DNA is taken from a bacterium 2.A piece is cut out using enzymes as ‘chemical scissors’ 3. A cell is taken from a human pancreas. The gene for insulin is cut from the chromosome 4. The insulin gene is put into the ring of bacteria DNA 5.The bacteria reproduce, making clones of themselves 6. The insulin is collected and purified ready for use

47. Pg 26 Ex 2

48.  SOLVE CRIMES  PATERNITY SUITS/Inheritance cases  IDENTIFICATION OF DEAD BODIES.  DIAGNOSIS OF INHERITED DISORDERS  DEVELOPING CURES FOR INHERITED DISORDERS

49. RNA is a small molecule It has a single strand It is made up of monomers called nucleotides A nucleotide consists of a  A sugar molecule = R ibose  A PHOSPHATE Portion  A NITROGEN base Cytosine Uracil Adenine Guanine

50. Three types and location 1. Messenger RNA (mRNA) - Nucleus and cytoplasm 2. Transfer RNA (tRNA) - cytoplasm 3. Ribosomal RNA (rRNA) - ribosome

51. FUNCTIONS Messenger RNA (mRNA) – transfers DNA code to ribosomes for translation. Acts as a template for protein synthesis. Transfer RNA (tRNA) – brings amino acids to ribosomes for protein synthesis. Ribosomal RNA (rRNA) – Ribosomes are made of rRNA and protein.

52. QUESTIONS 1.Name the types of RNA, state the location of each and give the function of each. 2.Draw a stick diagram to illustrate the structure of an RNA molecule with bases ACCGUU 3.Tabulate the differences between RNA and DNA.

53. Differences between DNA and RNA DNARNA Double strandSingle strand Deoxyribose sugarRibose sugar Thymine and AdenineAdenine and Uracil

54. PROTEIN SYNTHESIS TRANSCRIPTION In the nucleus. DNA unzips during replication. A DNA strand acts as a template for transcription. RNA nucleotides join complimentarily. mRNA molecule is formed. Process controlled by enzymes.

55. The mRNA moves out of the nucleus, through the nuclear pore, into the cytoplasm. It attaches to the ribosome.

56. TRANSLATION mRNA is attached to the ribosome with triplet bases (codons) exposed. tRNA with a complimentary RNA code (anticodon) bring specific amino acids (1 of 20) to the ribosome. Amino acids from different tRNA are joined by peptide bonds. A protein is made up of 50 or more amino acids.

57. A U G G G C U U A A A G C A G U G C A C G U U This is a molecule of messenger RNA. It was made in the nucleus by transcription from a DNA molecule. mRNA molecule codon

58. A U G G G C U U A A A G C A G U G C A C G U U A ribosome on the rough endoplasmic reticulum attaches to the mRNA molecule. ribosome

59. A U G G G C U U A A A G C A G U G C A C G U U It brings an amino acid to the first three bases (codon) on the mRNA. Amino acid tRNA molecule anticodon U A C A transfer RNA molecule arrives. The three unpaired bases (anticodon) on the tRNA link up with the codon.

60. A U G G G C U U A A A G C A G U G C A C G U U Another tRNA molecule comes into place, bringing a second amino acid. U A C C C G Its anticodon links up with the second codon on the mRNA.

61. A U G G G C U U A A A G C A G U G C A C G U U A peptide bond forms between the two amino acids. Peptide bond C C G U A C

62. A U G G G C U U A A A G C A G U G C A C G U U The first tRNA molecule releases its amino acid and moves off into the cytoplasm. C C G U A C

63. A U G G G C U U A A A G C A G U G C A C G U U C C G The ribosome moves along the mRNA to the next codon.

64. A U G G G C U U A A A G C A G U G C A C G U U Another tRNA molecule brings the next amino acid into place. C C G A A U

65. A U G G G C U U A A A G C A G U G C A C G U U A peptide bond joins the second and third amino acids to form a polypeptide chain. C C G A A U