4.0 CENTRAL DOGMA OF MOLLECULAR BIOLOGY V2.pptx

Learn about central dogma of mollecular

1. Central Dogma of Molecular Biology

2. Introduction: “Genetics - Central Dogma of Life ” http://www.youtube.com/watch?v=whV_CkKT7F0

3. The central dogma of molecular biology states that  DNA contains instructions for making a protein, which are copied by RNA.   RNA then uses the instructions to make a protein . In short: DNA → RNA → Protein, or DNA to RNA to Protein Central Dogma of Molecular Biology

4. 1. Replication : a double stranded nucleic acid is duplicated to give identical copies. This process perpetuates the genetic information. 2. Transcription : a DNA segment that constitutes a gene is read and transcribed into a single stranded sequence of RNA. The RNA moves from the nucleus into the cytoplasm. 3. Translation : the RNA sequence is translated into a sequence of amino acids as the protein is formed .

5. There are 4 different nucleotides : • dATP : deoxyadenosine triphosphate • dGTP : deoxyguanosine triphosphate • dTTP : deoxythymidine triphosphate • dCTP : deoxycytidine triphosphate

6. Figure2: From nucleotide to DNA. DNA is formed by coupling the nucleotides between the phosphate group from a nucleotide (which is positioned on the 5th C-atom of the sugar molecule) with the hydroxyl on the 3rd Catom on the sugar molecule of the previous nucleotide . To accomplish this, a diphosphate molecule is split off (and releases energy). This means that new nucleotides are always added on the 3’ side of the chain.

7. Figure 3 : The DNA in a cell. There are three types of genes : Protein-coding genes : these are transcribed into RNA and then translated into proteins . 2. RNA-specifying genes : these are only transcribed into RNA. 3. Regulatory genes : according to a narrow definition, these include only untranscribed sequences . The first two types are also called 'structural genes'.

8. Protein Structure Primary Structure Primary proteins are unbranched polymers of amino acids linked head to tail, from carboxyl group to amino group, through formation of covalent peptide bonds, a type of amide linkage. 2. Secondary Structure Structures resulting from these interactions constitute secondary structure for proteins. When a number of hydrogen bonds form between portions of the peptide chain in this manner, two basic types of structures can result α-helices and β-pleated sheets .

9. Protein Structure (cont.) 3. Tertiary Structure The folding of a single polypeptide chain in three-dimensional space is referred to as its tertiary structure. All of the information needed to fold the protein into its native tertiary structure is contained within the primary structure of the peptide chain itself. 4. Quaternary Structure Many proteins exist in nature as oligomers , complexes composed of (often symmetric) noncovalent assemblies of two or more monomer subunits. The way in which separate folded monomeric protein subunits associate to form the oligomeric protein constitutes the quaternary structure of that protein

10. Biological Functions of Protein Regulatory Proteins A number of proteins can regulate the ability of other proteins to carry out their physiological functions . (ex. insulin, the hormone regulating glucose metabolism in animals) 2. Transport Proteins A third class of proteins is the transport proteins . These proteins function to transport specific substances from one place to another. 3. Storage Proteins Proteins whose biological function is to provide a reservoir of an essential nutrient are called storage proteins . Because proteins are amino acid polymers and because nitrogen is commonly a limiting nutrient for growth, organisms have exploited proteins as a means to provide sufficient nitrogen in times of need.

11. Biological Functions of Protein (cont.) 4. Contractile and Motile Proteins Certain proteins endow cells with unique capabilities for movement. Cell division, muscle contraction, and cell motility represent some of the ways in which cells execute motion. 5. Structural Proteins An apparently passive but very important role of proteins is their function in creating and maintaining biological structures . Structural proteins provide strength and protection to cells and tissues. 6. Exotic Proteins Some proteins display rather exotic functions that do not quite fit the previous classifications. Monellin , a protein found in an African plant, has a very sweet taste and is being considered as an artificial sweetener for human consumption.

12. Biological Functions of Protein (cont.) 7. GLYCOPROTEINS Glycoproteins are proteins that contain carbohydrate . Proteins destined for an extracellular location are characteristically glycoproteins. 8. LIPOPROTEINS Blood plasma lipoproteins are prominent examples of the class of proteins conjugated with lipid . The plasma lipoproteins function primarily in the transport of lipids to sites of active membrane synthesis. 9. NUCLEOPROTEINS Nucleoprotein conjugates have many roles in the storage and transmission of genetic information . Ribosomes are the sites of protein synthesis . Virus particles and even chromosomes are protein–nucleic acid complexes.

13. Biological Functions of Protein (cont.) 10. PHOSPHOPROTEINS. These proteins have phosphate groups esterified to the hydroxyls of serine, threonine, or tyrosine residues. Casein, the major protein of milk, contains many phosphates and serves to bring essential phosphorus to the growing infant. 11. METALLOPROTEINS . Metalloproteins are either metal storage forms , as in the case of ferritin, or enzymes in which the metal atom participates in a catalytically important manner. 12. HEMOPROTEINS These proteins are actually a subclass of metalloproteins because their prosthetic group is heme , the name given to iron protoporphyrin IX. 13. FLAVOPROTEINS Flavin is an essential substance for the activity of a number of important oxidoreductases.

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15. Cell Reproduction and Genetics A . Cell Division 1. Mitosis 2. Meiosis B. Patterns of Inheritance C. Mendel’s Laws of Heredity D. Applications of Genetic Engineering

16. Introduction: The Cell Cycle (and cancer) http://www.youtube.com/watch?v=QVCjdNxJreE

17. Cell division is a part of the cell cycle . The cell cycle is an orderly set of stages that take place between the time a cell divides and the time the resulting cells also divide. The Cell Cycle The Stages of Interphase

18. The Cell Cycle Apoptosis

19. Mitosis “Mitosis: The Amazing Cell Process that Uses Division to Multiply!” http://www.youtube.com/watch?v=f-ldPgEfAHI

20. Mitosis

21. Mitosis in animal cells

22. Mitosis in animal cells Prophase. It is apparent during early prophase that cell division is about to occur. The centrosomes begin moving away from each other toward opposite ends of the nucleus . Spindle fibers appear between the separating centrosomes as the nuclear envelope begins to fragment, and the nucleolus begins to disappear. Prometaphase . During prometaphase , preparations for sister chromatid separation are evident. Kinetochores appear on each side of the centromere , and these attach sister chromatids to the kinetochore spindle fibers. These fibers extend from the poles to the chromosomes, which will soon be located at the center of the spindle. Metaphase. By the time of metaphase, the fully formed spindle consists of poles, asters, and fibers. The metaphase plate is a plane perpendicular to the axis of the spindle and equidistant from the poles.

23. Mitosis in animal cells Anaphase. At the beginning of anaphase, the centromeres uniting the sister chromatids divide . Then the sister chromatids separate, becoming daughter chromosomes that move toward the opposite poles of the spindle. Daughter chromosomes have a centromere and a single chromatid. Telophase. During telophase, the spindle disappears, and nuclear envelope components reassemble around the daughter chromosomes . Each daughter nucleus contains the same number and kinds of chromosomes as the original parental cell. Remnants of the polar spindle fibers are still visible between the two nuclei.

24. Mitosis in Plant Cells

25. “Meiosis” http://www.youtube.com/watch?v=VzDMG7ke69g

26. Meiosis, which requires two nuclear divisions , results in four daughter nuclei, each having one of each kind of chromosome and therefore half the number of chromosomes as the parental cell. First Division:

27. First Division:

28. First Division:

29. Second Division:

30. Second Division:

31. Comparison of Meiosis with Mitosis

32. Comparison of Meiosis with Mitosis

33. Father Mother The Human Life Cycle Spermatogenesis and Oogenesis in Humans In human males, meiosis is a part of spermatogenesis, which occurs in the testes and produces sperm. In human females, meiosis is a part of oogenesis, which occurs in the ovaries and produces eggs.

34. “Human Life Cycle” http://www.youtube.com/watch?v=7646b5Ee7BE

35. Mendel’s Laws of Heredity Why we look the way we look...

36. What is heredity ? The passing on of characteristics ( traits ) from parents to offspring Genetics is the study of heredity .

37. Studying genetics... ● More than 150 years ago, an Austrian monk named Johann Gregor Mendel observed that pea plants in his garden had different forms of certain characteristics. ● Mendel studied the characteristics of pea plants, such as seed color and flower color Developed the law of inheritance , which is now called as Mendel’s Principles ●

38. Mendel used peas... They reproduce sexually They have two distinct, male and female, sex cells called gametes Their traits are easy to isolate

39. Mendel crossed them Fertilization - the uniting of male and female gametes Cross - combining gametes from parents with different traits

40. What Did Mendel Find ? He discovered different laws and rules that explain factors affecting heredity.

41. Rule of Unit Factors Each organism has two alleles for each trait Alleles - different forms of the same gene Genes - located on chromosomes , they control how an organism develops

42. Phenotype & Genotype Phenotype - the way an organism looks – red hair or brown hair Genotype - the gene combination of an organism – AA or Aa or aa

43. Heterozygous & Homozygous Heterozygous - if the two alleles for a trait are different (Aa) Homozygous - if the two alleles for a trait are the same (AA or aa)

44. Rule of Dominance The trait that is observed in the offspring is the DOMINANT trait (UPPERCASE) The trait that disappears in the offspring is the recessive trait (lowercase) “In a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation. Offspring that are hybrid for a trait will have only the dominant trait in the phenotype.”

45. Law of Segregation The two alleles for a trait must separate when gametes are formed A parent randomly passes only one allele for each trait to each offspring “During the formation of gamete, each gene separates from each other so that each gamete carries only one allele for each gene.”

46. Law of Independent Assortment The genes for different traits are inherited independently of each other .

47. https://www.youtube.com/watch?v=Mehz7tCxjSE

48. Applications of Genetic Engineering In Medicine : Genetic engineering can be applied to: Manufacturing of drugs Creation of model animals that mimic human conditions and, Gene therapy Human growth hormones Monoclonal antibodies Vaccines

49. Applications of Genetic Engineering In Research: Genes and other genetic information from a wide range of organisms can be inserted into bacteria for storage and modification, creating genetically modified bacteria in the process. In Industry: Transformation of cells in organisms with a gene coding to get a useful protein.

50. Applications of Genetic Engineering In Agriculture: Genetically modified crops are produced using genetic engineering in agriculture. Such crops are produced that provide protection from insect pests. It is used or can be used in the creation of fungal and virus-resistant crops. Genetic engineering can be applied to other areas: Conservation Natural area management Microbial art

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52. Biotechnology and Bioethics

53. DNA Technology Genome - the complete genetic makeup of an organism G enetic engineering – a practice that has innumerable uses, from producing a product to treating cancer and genetic disorders Gene cloning - Another major biological application of cloning which is the production of many identical copies of a single gene. Transgenic organisms - organisms with foreign DNA or genes inserted into bacterium, plant or animal

54. Recombinant DNA Technology Recombinant DNA (rDNA) contains DNA from two or more different sources, such as the human cell and the bacterial cell in th e figure. Vector - a piece of DNA that can be manipulated such that foreign DNA can be added to it Plasmids - small accessory rings of DNA from bacteria that are not part of the Bacterial chromosome and are capable of self-replicating. Two enzymes are needed to introduce foreign DNA into Vector DNA: (1) a restriction enzyme to cleave the vector DNA (2) DNA ligase to seal DNA into an opening created by the restriction enzyme

55. DNA Analysis DNA fingerprint – when a s maller fragments move farther through the gel than larger fragments , and result in a pattern of distinctive bands. Short tandem repeat (STR) - are the same short sequence of DNA bases that recur several times, STR profiling is advantageous because it doesn’t require the use of restriction enzymes

56. Biotechnology Products Genetically modified organisms (GMOs) - transgenic bacteria, plants, and animals Biotechnology - products produced by GMOs. Transgenic Bacteria - Recombinant DNA technology is used to produce transgenic bacteria , which are grown in huge vats called bioreactors . - have also been engineered to promote the health of plants, extract minerals, and produce medically important chemicals.

57. Transgenic Plants - engineered to resist herbicides and pests , are commercially available. - Techniques have been developed to introduce foreign genes into immature plant embryos or into plant cells called protoplasts that have had their cell wall removed. It is possible to treat protoplasts with an electric current while they are suspended in a liquid containing foreign DNA. Transgenic Animals - have been given various genes, in particular the one for bovine growth hormone (BGH). Cloning of whole animals is now possible. - Techniques have been developed to insert genes into the eggs of animals. It is possible to microinject foreign genes into eggs by hand, but another method uses vortex mixing. The eggs are placed in an agitator with DNA and silicon-carbide needles.

58. Gene Therapy is the insertion of genetic material into human cells for the treatment of genetic disorders and various other human illnesses, such as cardiovascular disease and cancer.

59. The figure describes an ex vivo methodology for treating children who have SCID (severe combined immunodeficiency). These children lack the enzyme ADA (adenosine deaminase), which is involved in the maturation of T and B cells. Therefore, these children are prone to constant infections and may die without treatment. Ex Vivo Gene Therapy

60. In Vivo Gene Therapy - In gene therapy trials, the gene needed to cure cystic fibrosis is sprayed into the nose or delivered to the lower respiratory tract by an adenovirus vector or by using liposomes. So far, these treatments have met with limited success, but investigators are trying to improve uptake by using a combination of different vectors.

61. Proteomics - the study of which genes are active in producing proteins in which cells and under which circumstances. - the use of computers to assist with analysis of data from proteomics and functional and comparative genomics. Bioinformatics

62. https://www.youtube.com/watch?v=cY-7gwnWESk BIOETHICS INTRODUCTION:

63. Bioethics It is the study of ethical, social, and legal issues that arise in biomedicine and biomedical research. Bioethics includes: Medical Ethics - focuses on issues in health care Research Ethics - focuses issues in the conduct of research Environmental Ethics – focuses in relationship between human activities and the environment Public Health Ethics - addresses ethical issues in public health

64. PRINCIPLES OF BIOETHICS PRINCIPLE OF AUTONOMY A person should be free to perform whatever action he/she wishes, regardless of risks or foolishness as perceived by others, provided it does not impinge on the autonomy of others

65. 2. PRINCIPLE OF BENEFICENCE One should render positive assistance to others [and abstain from harm (minimalist principle of nonmaleficence ) by helping them to achieve benefits which will further their important and legitimate interests Harm principle as a form of beneficence - Prevent an individual from harming another

66. 3. PRINCIPLE OF JUSTICE One should give to persons what they are owed , what they deserve, or what they can legitimately claim, treating equals equally unless there is A morally relevant difference requiring persons to be treated unequally/differently; consideration must often be given to A proper allocation of benefits and burdens within the social context

67. 4. PRINCIPLE OF PARENTALISM One should restrict an individual’s chosen action against his/her consent in order to prevent that individual from self-harm, or to secure for that individual a good which he/she might not otherwise achieve FORMS OF PARENTALISM Strong Parentalism - restrict the liberty of those who are functionally autonomous Weak Parentalism - restrict the actions of those with permanent severely diminished autonomy

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