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Cell Theory and Structure

Cell Theory and Structure. Development of the Light Microscope Evolution of the Cell Theory Spontaneous Generation Disproven Histochemistry , Mitosis, and Meiosis Classes of Biochemicals in Cells Electron Microscopy and Ultrastructure. The Microscope.

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Cell Theory and Structure

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  1. Cell Theory and Structure

  2. Development of the Light Microscope • Evolution of the Cell Theory • Spontaneous Generation Disproven • Histochemistry, Mitosis, and Meiosis • Classes of Biochemicals in Cells • Electron Microscopy and Ultrastructure

  3. The Microscope • An understanding of cells and the structure of cells had to wait until structures so small could be visualized by magnification.

  4. Origin of the Microscope • The first record of the invention of a microscope was by Hans and Zacharias Janssen (Netherlands) in 1590? • Galileo Galileiimproved the microscope in 1609 (in the same way that he improved the telescope) and by 1624-1625 published magnified drawings of insects. • Suffered from chromatic and spherical aberrations Galileo’s first microscope from 1609 Illustrations of honey bees made with an improved Galileo microscope in 1630

  5. Antonie Philips van Leeuwenhoek Made a powerful single-lens microscope with which he observed many types of unicells and tissues. He even drew bacteria. A single-lens microscope 1632-1723, Netherlands His drawing of an ash stem section

  6. Robert Hooke’s Micrographia • Hooke was intrigued by the reports sent by van Leeuwenhoek and built his own microscope on the design of Galileo • He confirmed many of the observations that van Leeuwenhoek reported • Made many of his own original observations • Published Micrographia in 1665

  7. Much of the microscopic work of the rest of the 17th and 18th centuries was descriptive [and there was much to describe]. • Near the beginning of the 19th century, microscopes were made that reduced the problems of chromatic aberration Trunnion Model microscope made by Charles A. Spencer (1813-1881), US manufacturer of microscopes

  8. Ernst Karl Abbe • Partner of Carl Zeiss • Optical physicist • Invented the apochromatic lens and corrections to spherical aberration • Sought to maximize resolution of the light microscope • Demonstrated the limit of resolution around 0.5μm 1840-1905, Germany

  9. The Cell Theory • …also, by the early part of the 19th century enough biological material had been observed to begin to make generalizations.

  10. Matthias JakobSchleiden • A botanist and microscopist • In 1838 declared that the plant organism is made of cells • He accepted the importance of the nucleus, discovered by Robert Brown (1773-1858), and speculated on its role in cell division 1804-1881, Germany

  11. Theodor Schwann • He was a zoologist and a microscopist • Physiologist and microanatomist • Discovered the connection between yeast and fermentation • Following Schwann’s pronouncement, declared that animals, too, are made of cells as the fundamental building blocks 1810-1882, Germany

  12. Virchow and Remak Virchow’s cell theory • Rudolph Carl Virchow (1821-1902, Germany) suggested that disease is a cellular problem • He stated that all cells come from pre-existing cells, a theory stated earlier by Robert Remak(1815-1865, Poland) Virchow (1821-1902) Remak (1815-1865)

  13. The Question of Spontaneous Generation • Spontaneous generation clearly stated for some plants and animals by Aristotle in History of Animals and On the Generation of Animals • Francesco Redi(1626-1697, Italy) • John Tuberville Needham (1713-1781, England) boiled broth and then sealed after a time to allow the vital force to enter • LazzaroSpallanzani(1729-1799, Italy) boiled broth and immediately sealed it

  14. Louis Pasteur • Disproved spontaneous generation • Causes of fermentation • Germ theory of disease • Immunology and vaccination 1822-1895, France

  15. The Cell Theory by 1858 • All living organisms are composed of one or more cells. • The cell is the most basic unit of structure, function, and organization in all organisms. • All cells come from pre-existing, living cells.

  16. Histology and Paul Ehrlich • Aniline dyes had been derived from coal tars in the early part of 19th Century • Karl Weigert (1845-1904, Germany) used an aniline dye to stain bacteria • Ehrlich experimented with staining human tissues • He used chemical treatments to serve as the first chemotherapy (used Methylene Blue for syphilis) 1854-1915, Germany The use of aniline dye to stain white blood cells

  17. Development of Optical Staining Polarized light Bright field Darkfield Phase-Contrast Differential Interference Contrast Fluorescence Imaging

  18. Walther Flemming • Used aniline dyes to visualize nuclei and chromosomes • All nuclei come from other nuclei • He discovered and described the mitotic cell cycle in cells from the gills and fins of salamanders. 1843-1905, Germany Published in 1882

  19. The Cell Cycle: Mitosis

  20. Reduction Division: Meiosis • First described by Oskar Hertwig(1849-1922, Germany) in 1876 in the formation of sea urchin eggs. • Described again by Edouard van Beneden(1846-1910, Belgium) in 1890 in the formation of Ascaris eggs. • August Weismann (1834-1914, Germany) noted in 1911 that the reduction of chromosome numbers, employing meiosis, was necessary if nuclei were to fuse in sexual reproduction

  21. Meiosis

  22. Major Classes of Biochemical Compounds in Living Cells: A Very Brief Synopsis of Chapter 22 • Lipids: made of glycerol and fatty acids • Carbohydrates: polymers of D-sugar units • Proteins: polymers of L-amino acid units • Nucleic Acids: polymers of nucleotides, each consisting of a phosphate, a D-sugar, and a nitrogenous base (pyrimidines and purines)

  23. Lipids

  24. Carbohydrates

  25. Proteins

  26. Nucleic Acids

  27. Electron Microscopy • Two types: Transmission (TEM) and Scanning (SEM)

  28. Transmission Electron Microscopy • Leo Szilard (1928) filed patent for electron microscope in concept • The prototype built in 1931 by Ruska and Knoll • Resolution limit for light microscope ~2,000X; but the limit for TEM ~2 millionX Max Knoll (1897-1969, Germany, left) and Ernst Ruska (1906-1988, Germany, right) with first TEM

  29. Scanning Electron Microscopy Vladimir Kosmich Zworykin (1888-1982, Russia and USA) invented SEM and television (both based on raster principle) With early television (kinetoscope) in 1929

  30. Details of Subcellular Structures with EM Membranes

  31. Details of Subcellular Structures with EM Nucleus

  32. Details of Subcellular Structures with EM Chloroplast

  33. Details of Subcellular Structures with EM Mitochondria

  34. Details of Subcellular Structures with EM Endoplasmic Reticulum

  35. Details of Subcellular Structures with EM Flagellum or Cilium

  36. Current View of the Cell Theory • All known living things are made up of one or more cells. • All living cells arise from pre-existing cells by division. • The cell is the fundamental unit of structure and function in all living organisms. • The activity of an organism depends on the total activity of independent cells. • Energy flow occurs within cells. • Cells contain hereditary information (DNA) which is passed from cell to cell during cell division. • All cells are basically the same in chemical composition in organisms of similar species.

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