Lec 1 Introduction to molecular biology.pptx

Introduction to molecular biology.pptx

1. Molecular Biology Course Dr. Abdifatah A. Jalei (PhD in Molecular Biology) Introduction to Molecular Biology

2. OBJECTIVES At the end of studying this unit, you should be able to: 1. Define molecular biology. 2. Summarize the history of molecular biology. 3. Outline its relationship with other biological sciences. 4. Describe the techniques of molecular biology. 5. Identify the significance of molecular biology.

3. Molecular Biology The study of molecular basis of life, Or The branch of biology that deals with structure , function & manipulation of the macromolecules (Proteins & nucleic acid) essential to life.

4. Molecular Biology Molecular biology is a branch of biology that study gene structure and function at the molecular level. The Molecular biology field overlaps with other areas, particularly genetics and biochemistry. The Molecular biology allows the laboratory to be predictive in nature; events that occur in the future.

5. Molecular biologist Studies how molecules interact with one another in living organisms to perform the functions of life. Conduct experiments to investigate the structure, function, processing, regulation and evolution of biological molecules and their interactions with one another — providing micro-level insights into how life works. Although there are many kinds of molecules in every living thing, most molecular biologists focus on genes and proteins.

6. Molecular biologists work to identify and understand the parts of biological pathways. Proteins can: Regulate and impact each other Respond to signals from genes Respond to signals from outside a cell

7. A Brief History The term molecular biology was first used in 1945 by William Astbury. Since the late 1950s and early 1960s, molecular biologists have learned to Characterize, isolate, and manipulate the molecular components of cells and organisms, which are: DNA, the storage of genetic information RNA Proteins, the major structural and enzymatic type of molecule in cells.

8. Molecular Biology – A Journey Microscopic biology began in 1665 Robert Hooke (1635-1703) discovered organisms are made up of cells Matthias Schleiden (1804-1881) and Theodor Schwann (1810-1882) further expanded the study of cells in 1830s Robert Hooke Theodor Schwann Matthias Schleiden

9. Major events in the history of Molecular Biology 1800 - 1870 1865 Gregor Mendel discover the basic rules of heredity of garden pea. An individual organism has two alternative heredity units for a given trait (dominant trait vs. recessive trait) 1869 Johann Friedrich Miescher discovered DNA and named it nuclein. Mendel: The Father of Genetics Johann Miescher

10. Major events in the history of Molecular Biology 1880 - 1900 1881 Edward Zacharias showed chromosomes are composed of nuclein . 1899 Richard Altmann renamed nuclein to nucleic acid. By 1900, chemical structures of all 20 amino acids had been identified

11. Major events in the history of Molecular Biology 1900-1911 1902 - Emil Hermann Fischer wins Nobel prize: showed amino acids are linked and form proteins 1911 – Thomas Hunt Morgan discovers genes on chromosomes are the discrete units of heredity 1911 Pheobus Aaron Theodore Lerene discovers RNA Emil Fischer Thomas Morgan

12. Major events in the history of Molecular Biology 1940 - 1950 1941 – George Beadle and Edward Tatum identify that genes make proteins 1950 – Edwin Chargaff find Cytosine complements Guanine and Adenine complements Thymine. George Beadle Edward Tatum Edwin Chargaff

13. Major events in the history of Molecular Biology 1950 - 1952 1950s – Mahlon Bush Hoagland first to isolate tRNA 1952 – Alfred Hershey and Martha Chase make genes from DNA Mahlon Hoagland

14. Major events in the history of Molecular Biology 1952 - 1960 1952-1953 James D. Watson and Francis H. C. Crick deduced the double helical structure of DNA 1956 George Emil Palade showed the site of enzymes manufacturing in the cytoplasm is made on RNA organelles called ribosomes. James Watson, Francis Crick George Emil Palade

15. Major events in the history of Molecular Biology 1970 1970 Howard Temin and David Baltimore independently isolate the first restriction enzyme This means that: DNA can be cut into reproducible pieces at specific site by restriction enzymes called endonuclease The pieces can be linked to bacterial vectors and introduced into bacterial hosts. This is called (gene cloning or recombinant DNA technology)

16. Major events in the history of Molecular Biology 1970- 1977 1977 Phillip Sharp and Richard Roberts demonstrated that pre-mRNA is processed by the excision of introns and exons are spliced together. Phillip Sharp Richard Roberts

17. Major events in the history of Molecular Biology 1986 - 1995 1986 Leroy Hood: Developed automated sequencing mechanism 1986 Human Genome Initiative announced 1995 Moderate- resolution maps of chromosomes 3, 11, 12, and 22 were published These maps provide the locations of “ markers ” on each chromosome to make locating genes easier Leroy Hood

18. Major events in the history of Molecular Biology 1995-1996 1995 John Craig Venter: First bacterial genomes sequenced 1995 Automated fluorescent sequencing instruments and robotic operations 1996 First eukaryotic genome - yeast-sequenced. John Craig Venter

19. Molecular Biology 1997-1999 1999 First human chromosome (number 22 ) sequenced Molecular Biology 2000-2001 2001 International Human Genome Sequencing published the first draft of the sequence of the human genome. Major events in the history of Molecular Biology

20. Major events in the history of Molecular Biology 2003- Present April 2003 Human Genome Project Completed Mouse genome is sequenced. April 2004 Rat genome sequenced. Next-generation sequencing – genomes being sequenced by the dozen

21. Importance of molecular biology Molecular Biology is the foundation for many other fields, including genetics, biotechnology, and medicine. It has revolutionized our understanding of life processes. It plays a crucial role in medical diagnostics, drug development, genetic engineering etc.

22. Relationship With Other Biological Sciences Molecular biology concerns itself with understanding the interactions between the various systems of a cell, including the interrelationship of DNA, RNA and protein synthesis and learning how these interactions are regulated. Schematic relationship between biochemistry, genetics and molecular biology Function Genes Proteins Biochemistry Molecular Biology Genetics

23. The Differences in Molecular Biology, Biochemistry & Genetics The three sciences all concern themselves with details of how organisms work at the molecular level. However, each focuses on a different area and have different applications. Biochemistry : Primarily examines a wide range of molecules, i.e. , proteins, nucleic acids, and the chemical effects that occur when substances are present in larger quantities, such as the effects of venoms.

24. Conti.. Genetics: Genetics is concentrated on heritable traits and the impact of changes in the genetic code on an organism. This heritability focus often leads to the study of genetics at the population level, making it a broader and more extensive field compared to molecular biology.

25. Conti.. Molecular biology overlaps with other areas of biology and chemistry, particularly genetics and biochemistry. It is the joining of aspects between genetics and biochemistry.

26. The Complex Relationship of Genes & Proteins Genes are segments of information stored on gigantic nucleic acid molecules. Proteins perform a huge diversity of functions within living cells and genes contain the information required to make more proteins.

27. Components Involve in Molecular Biology All Life depends on 3 critical molecules DNA RNA Protein

28. Structure Static Function Dynamic Function Dynamic English alphabet 26 letters Life alphabet 4 letters A, T, G, C Inside a Living Cell

29. All Life depends on 3 critical molecules DNAs. Hold information on how cell works RNAs. Act to transfer short pieces of information to different parts of cell Provide templates to synthesize into protein Proteins. Form hormones and enzymes that send signals to other cells and regulate gene activity Form body’s major components (e.g. hair, skin, etc.).

30. The Biomolecules DNA mRNA Protein Gene

31. DNA, RNA, and the Flow of Information

32. mRNA Protein Transcription Translation Cytoplasm Nucleus DNA The Central Dogma

33. From DNA to protein

34. The Three Domains of Life Current research theories support the division of living organisms into three domains Prokaryotic Eukaryota Archaea living in the most inhospitable regions Thermo philes tolerate extremely high temperatures Halo philes tolerate very high salt concentrations Methan ogens produce methane as a by-product of metabolism

35. Methods and Techniques in Molecular Biology

36. Molecular Biology Laboratory Methods Molecular biology is perhaps most famous for its distinctive suite of laboratory methods. Molecular biologists make extensive use of: Molecular cloning Polymerase Chain reaction Gel electrophoresis Blotting DNA sequencing These techniques facilitate quantifying molecules of interest.

37. Application of molecular biology Diagnosis Paternity testing: genetic fingerprints; Paternity proof. Forensic analysis Gene therapy Drug design

38. Molecular Diagnosis Detection of infectious pathogens: Genes from pathogens can be amplified to identify them. Defective genes can be amplified to diagnose many genetic disorders. Malignancies detection & follow up. Prenatal screening for genetic disorders.

39. 40 History of Molecular Diagnostics 1865 Gregor Mendel, Law of Heredity 1866 Johann Miescher, Purification of DNA 1953 1970 Recombinant DNA Technology 1977 DNA sequencing 1985 In Vitro Amplification of DNA (PCR) 2001 The Human Genome Project Watson and Crick, Structure of DNA The Molecular Biology Timeline Sickle Cell Anemia Mutation 1949 Sequencing technologies and Genome sequencing 2005-11

40. Assignment 1 The differences in Molecular Biology, Biochemistry & Genetics. Discuss briefly each of the following areas: Focus or Goal Key areas

41. Thank you