1. CHAPTER 12 DNA & RNA

2. Why do Animals not look the same?

10. 12.1DNA 12.2Chromosomes and DNA Replication 12.3 RNA and Protein Synthesis 12.4 Mutations 12.5 Gene Regulation Chapter 12 DNA and RNA

11. Griffith’s Experiment

12. AVERY AND DNA

14. Hershey-Chase Experiment

15. Learning Outcomes After this section, you should be able to: describe the basic unit of DNA – the nucleotide; state and apply the rule of complementary base pairing. 12.1 DNA

16. A cell contains a nucleus and in the nucleus are chromatin strands that are made up of proteins and deoxyribonucleic acid (DNA). an animal cell nucleus with chromatin strands inside DNA molecule protein molecules 12.1 DNA

17. How is DNA organised inside the cell nucleus? Each DNA molecule consists of two parallel strands twisted around each other to form a double helix. During cell division, the chromatin threads coil more tightly to form chromosomes inside the cell nucleus. A molecule of DNA is wrapped around proteins to form a single chromatin thread. 12.1 DNA

18. What is DNA? A molecule that carries genetic information. It is made up of nucleotides. A nucleotide is made up of: (1) a deoxyribose (sugar) molecule, (2) a phosphate group, and (3) a nitrogen-containing base - adenine (A), thymine (T), guanine (G), or cytosine (C). 12.1 DNA

19. Possible nucleotides that can be formed: adenine nucleotide thymine nucleotide guanine nucleotide cytosine nucleotide bases sugar-phosphate backbone polynucleotide These nucleotides can be joined together to form polynucleotides. 12.1 DNA

20. The DNA molecule is made of two anti-parallel polynucleotide strands. (The two strands run in opposite directions.) The bases on one strand form bonds with the bases on the other strand according to the rule of base pairing. 12.1 DNA

21. Rule of base pairing Adenine (A) bonds with thymine (T) Guanine (G) bonds with cytosine (C) These pairs of bases are called complementary bases. Adenine (A) and thymine (T) are complementary bases. Guanine (G) and cytosine (C) are complementary bases. 12.1 DNA

22. The two anti-parallel strands of the DNA molecule coil to form a double helix structure. bases sugar-phosphate backbone coiling of DNA the double helix structure of DNA 12.1 DNA

23. Mini project Edwin Chargaff was the biochemist who discovered that: the percentage of adenine = the percentage of thymine and the percentage of guanine = the percentage of cytosine in the DNA of a cell. Find out more about Edwin Chargaff and his contributions to molecular genetics. Prepare a poster and a short presentation on your findings. 12.1 DNA

24. Checkpoint 2.State the complementary base pair to the strand shown below: Answer: 1.DNA molecules found in the cell nucleus are compacted to form chromatin strands. Other than DNA, what other molecule is found in chromatin strands? Answer: Protein molecules 12.1 DNA

25. 3. State the ratio of: (1) adenine : thymine, and (2) guanine : cytosine in the DNA of a cell. Answer: (1)1 : 1 (2)1 : 1 4.The strands in a DNA molecule are ___________. The strands coil together to form a ______ ______ structure. anti-parallel double helix 12.1 DNA

26. 12.1 DNA Text book Questions Page 294 Q1-5

27. 12.1DNA 12.2Chromosomes and DNA Replication 12.3 RNA and Protein Synthesis 12.4 Mutations 12.5 Gene Regulation Chapter 12 DNA and RNA

28. Chapter 12.2 Prokaryote vs Eukaryote

29. Chapter 12.2 Prokaryote vs Eukaryote

30. Chapter 12.2 Nucleosomes

31. Chapter 12.2 DNA Replication

32. Chapter 12.2 DNA Replication

33. Review According to Chargaff's rule, the following proportion exists in DNA. A)C=G B)C»T C)C»G D)C=T Chapter 12.2

34. Review According to Chargaff's rule, the following proportion exists in DNA. A)C=G B)C»T C)C»G D)C=T Chapter 12.2

35. Review All of the following were outcomes of Avery's experiment on "the active principle" except A)the array of the elements of purified principle agreed closely with DNA and the principle centrifuged to the same level as DNA. B)protein digesting enzymes did not affect the sample C)the extraction of lipids and proteins from the principle only slightly reduced its activity D)DNA-digesting enzyme, DNase, destroyed all transcription activity. Chapter 12.2

36. Review All of the following were outcomes of Avery's experiment on "the active principle" except A)the array of the elements of purified principle agreed closely with DNA and the principle centrifuged to the same level as DNA. B)protein digesting enzymes did not affect the sample C)the extraction of lipids and proteins from the principle only slightly reduced its activity D)DNA-digesting enzyme, DNase, destroyed all transcription activity. Chapter 12.2

37. Review The fact that some viruses use DNA to direct their heredity was demonstrated by A)finding radioactive sulfur from a bacteriophage in a bacterium. B)finding radioactive phosphorus from a bacterium in a bacteriophage. C)finding that radioactive phosphorus from a bacteriophage had mutated in bacterium. D)finding radioactive phosphorus from a bacteriophage in a bacterium. E)finding radioactive sulfur from a bacterium in a bacteriophage. Chapter 12.2

38. Review The fact that some viruses use DNA to direct their heredity was demonstrated by A)finding radioactive sulfur from a bacteriophage in a bacterium. B)finding radioactive phosphorus from a bacterium in a bacteriophage. C)finding that radioactive phosphorus from a bacteriophage had mutated in bacterium. D)finding radioactive phosphorus from a bacteriophage in a bacterium. E)finding radioactive sulfur from a bacterium in a bacteriophage. Chapter 12.2

39. Review In DNA guanine always pairs with A)Adenine B)Cytosine C)Guanine D)Thymine E)Uracil Chapter 12.2

40. Review In DNA guanine always pairs with A)Adenine B)Cytosine C)Guanine D)Thymine E)Uracil Chapter 12.2

41. Review With few exceptions, all nuclei of eukaryotes contain A)genes to specify the portion of the organism in which they are found B)all the information needed for growing the whole organism C)all of the chromosomes except sex chromosomes which are restricted to sex organs D)single stranded DNA E)only euchromatin except in the case of the Y- chromosome Chapter 12.2

42. Review With few exceptions, all nuclei of eukaryotes contain A)genes to specify the portion of the organism in which they are found B)all the information needed for growing the whole organism C)all of the chromosomes except sex chromosomes which are restricted to sex organs D)single stranded DNA E)only euchromatin except in the case of the Y- chromosome Chapter 12.2

43. Review In DNA, thymine always pairs with A)Adenine B)Cytosine C)Guanine D)Thymine E)Uracil Chapter 12.2

44. Review In DNA, thymine always pairs with A)Adenine B)Cytosine C)Guanine D)Thymine E)Uracil Chapter 12.2

45. Review Each unit of a nucleic acid consisting of a sugar, attached phosphate group, and base is a A)Nucleolus B)Nucleotide C)Nucleosome D)Histone E)Genetisome Chapter 12.2

46. Review Each unit of a nucleic acid consisting of a sugar, attached phosphate group, and base is a A)Nucleolus B)Nucleotide C)Nucleosome D)Histone E)Genetisome Chapter 12.2

47. Review A DNA molecule has the same amount of adenine and thymine. A)True B)False Chapter 12.2

48. Review A DNA molecule has the same amount of adenine and thymine. A)True B)False Chapter 12.2

49. Review In the DNA molecule: A)adenine pairs with thymine B)guanine pairs with thymine C)cytosine pairs with thymine D)adenine pairs with cytosine E)All of the above are possible.A DNA molecule has the same amount of adenine and thymine. Chapter 12.2

50. Review In the DNA molecule: A)adenine pairs with thymine B)guanine pairs with thymine C)cytosine pairs with thymine D)adenine pairs with cytosine E)All of the above are possible.A DNA molecule has the same amount of adenine and thymine. Chapter 12.2

51. Review If one side of a DNA molecule contains the following sequence of nucleotides, AGTCCG, the complementary sequence on the other side would be: A)GCCTGA B)AGTCCG C)TCAGGC D)CTGAAT E)none of the above Chapter 12.2

52. Review If one side of a DNA molecule contains the following sequence of nucleotides, AGTCCG, the complementary sequence on the other side would be: A)GCCTGA B)AGTCCG C)TCAGGC D)CTGAAT E)none of the above Chapter 12.2

53. Review During your summer job at Virotech, you isolate a previously unknown virus. Analysis of its genome reveals that it is composed of a double stranded DNA molecule containing 14% T (thymine). Based on this information, what would you predict the %C (cytosine) to be? A)14% B)28% C)36% D)72% E)Cannot be determined from the information given. Chapter 12.2

54. Review During your summer job at Virotech, you isolate a previously unknown virus. Analysis of its genome reveals that it is composed of a double stranded DNA molecule containing 14% T (thymine). Based on this information, what would you predict the %C (cytosine) to be? A)14% B)28% C)36% D)72% E)Cannot be determined from the information given. Chapter 12.2

55. Review Text book questions page 299 1-6 Chapter 12.2

56. 12.1DNA 12.2Chromosomes and DNA Replication 12.3 RNA and Protein Synthesis 12.4 Mutations 12.5 Gene Regulation Chapter 12 DNA and RNA

57. How are proteins made? 12.3 RNA and Protein Synthesis

58. Types of RNA Chapter 12 DNA and RNA

60. It is a temporary molecule that is made when needed. It is a permanent molecule in the nucleus. It is a small soluble molecule.It is a large insoluble molecule. No fixed ratio between A and U and between G and C. Ratio of A:T and G:C is 1:1. Nitrogen-containing bases are adenine (A), uracil (U), guanine (G) and cytosine (C). Nitrogen-containing bases are adenine (A), thymine (T), guanine (G) and cytosine (C). Sugar unit is ribose.Sugar unit is deoxyribose. RNADNA (double helix) DNA vs. RNA 17.2 Genes

61. The DNA template is first transcribed into a messenger RNA (mRNA) molecule through a process called transcription. Transcription occurs in the nucleus of the cell. During transcription, the DNA codons in the gene are converted into RNA codons. The mRNA molecule is then translated into polypeptides through the process of translation. Translation occurs in the cytoplasm of the cell. How are proteins made? 12.3 RNA and Protein Synthesis

62. DNA template transcription mRNA - RNA contains uracil (U) instead of thymine (T) polypeptide translation 17.2 Genes

63. The DNA template is first transcribed into a messenger RNA (mRNA) molecule through a process called transcription. Transcription occurs in the nucleus of the cell. During transcription, the DNA codons in the gene are converted into RNA codons. The mRNA molecule is then translated into polypeptides through the process of translation. Translation occurs in the cytoplasm of the cell. How are proteins made? 12.3 RNA and Protein Synthesis

64. 17.2 Transcription and Translation Genes 1 2 template strand gene unzips transcription ribosome mRNA mRNA molecule 3 attachment to ribosome

65. Translation Attachment of the mRNA to a ribosome is the start of the translation process. The codons on the mRNA tells the cell what amino acids to attach together and in what order. peptide bond amino acids attached to tRNA ribosome codon 17.2 Genes

66. Attachment of mRNA with ribosome mRNA is then read by codons (every 3 bases) Bases found on mRNA will be complementary to tRNA (transfer) bases. Thus, formation of polypeptide chain begins with bonding of other tRNA (different amino acids). Polypeptide chain elongates with reading of every 3 bases on mRNA by ribosome. It will elongate till it reaches the termination codon found on mRNA. Once completed, ribosome shall release mRNA and protein is released into cytoplasm for processing.

67. RNA Editing

69. The Genetic Code

74. Review Text Book Page 306 Question 1-5

75. 12.4 Mutations

76. 12.4 Point Mutations

77. 12.4 Frame Shift Mutations

78. 12.4 Chromosome Mutations

79. Review Text book Page 308 Question 1-4

80. 12.5Gene Regulation

82. 12.5 Differentiation

83. 12.5 Hox genes Any of the developmental control genes involved in making and identity of each body segment. Mainly during early embryonic development.

84. 12.5 Hox genes

85. Review Text book Page 312 Questions 1-5

86. REMINDER Nucleotide

87. REMINDER Nucleotide

88. REMINDER Nucleotide

89. Learning Outcomes After this section, you should be able to: state that DNA molecules contain the genetic code; state what is meant by the genetic code; state that a gene is a specific sequence of nucleotides in a DNA molecule that controls the production of a polypeptide. 12.2 Genes

92. The Eye Colour is Green due to proteins. Proteins are formed thanks to genes found in the DNA that encodes for eye colour. Over time, eye colour may change (either lighten or darken) This is due to different expressions of the gene which leads to different release of proteins thus a different colour!

93. What is a gene? It is a segment of DNA. The nucleotide sequence in the gene determines the protein formed thus the hereditary trait. Since there are four different nucleotides, for a gene made up of n nucleotides, there are 4 n different combinations of nucleotides. gene DNA polypeptide coded by the gene 17.2 Genes

94. Three nucleotides in a gene form a codon and each codon codes for one amino acid. The genetic code states which amino acid each codon codes for. Example: Codon (DNA) Amino acid coded for TACMethionine (M) TATAlanine (A) CATLysine (K) GAGGlutamic acid (E) ACASerine (S) 17.2 Genes

96. A change in the nucleotide sequence of a gene is termed as gene mutation. A mutation may or may not lead to a change in the protein product. A change in the protein product may or may not lead to an observable phenotype. Recall Two examples of gene mutation was mentioned in Chapter 16. Can you state the two examples? (1)Albinism (2)Sickle-cell anaemia What happens when the nucleotide sequence in a gene is altered? 17.2 Genes

97. Gene mutation refers to the change in genetic material of a gene. Examples of gene mutation: (1) Albinism - mutation in the gene causes an absence or defect in the enzyme that produces pigment Revision (2) Sickle-cell anaemia - mutation in the gene causes the protein product to differ from the normal protein by a single amino acid, causing red blood cells to be sickle- shaped 17.2 Genes

98. How are proteins made?