BIOCHEMISTRY - Textbook - Ostapchenko L. I. - 2012

Chapter 3. THE CELL AND EXTRACELLULAR MATRIX

The foundation for the Discovery of the Cell was the invention of the Microscope by Z. Janssen (1590) and its application to observing biological objects. R. Hooke, while examining cork slices under a microscope, discovered that they consisted of many small compartments resembling a honeycomb (1665), which he named Cells (from the Latin cellula – small room). In the second half of the XVII century, M. Malpighi and N. Grew also noted the cellular Structure of many plant specimens. In 1674, A. van Leeuwenhoek was the first to discover (observe) unicellular organisms in Water. In the second decade of the XIX century, while studying cell contents, J. Purkinje introduced METABOLISM/2.html">THE CONCEPT OF cell protoplasm (from the Greek protos – first, plasma – formation). In 1825 by J. Purkinje, in 1831 by R. Brown, and in 1839 by T. Schwann, the Cell Nucleus was discovered in PLANT AND ANIMAL cells, which became a crucial step in establishing common features between plant and animal cells. By the end of the XIX century, a whole constellation of top-tier researchers had dedicated themselves to The Study of The Cell: H. Fol, O. Bütschli, O. Hertwig, W. Flemming, E. Strasburger, and others. Thanks to their work, The structure of the cell nucleus was studied in detail, and a cytological analysis of mitosis, Meiosis, and Fertilization was performed. By the end of the XIX century, biologists had accumulated sufficient data regarding the morphological aspects of mitosis. The first attempts to analyze the Causes and Mechanisms regulating mitotic activity were made by A. Gurwitsch (1923) and W. Bullough (1948).

In the XX century, there arose both the necessity and the capability to investigate living cells directly. Beginning in 1907, the tissue culture method was introduced (R. Harrison), followed by cell culture Methods in the 1950s and organ culture methods in the 1970s. Crucial for in vivo cell research was the Introduction of the micromanipulator, as well as dark-field and luminescence Microscopy (1901–1916), which paved the way for major breakthroughs following The Development of the fluorescent antibody technique (A. Coons, 1941–1942). An important role also belongs to cyto- and histochemical methods, which originate from the research of F. Raspail, who was the first to use the iodine reaction for starch (the 1830s). These methods continue to be used today to study biochemical processes within the living cell.

Along with cytochemical methods, important techniques include differential centrifugation (first used by C. Bensley and N. Hoerr for mitochondrial analysis), UV Light absorption (T. Caspersson, 1940), radioactive isotopes and autoradiography (G. de Hevesy, 1950; J. Boyd, 1957), including autoradiography using the DNA precursor ³H-thymidine (H. Quastler, F. Sherman, 1959). Electron microscopy became a major methodological breakthrough in cell research. It made it possible to "visualize" all cellular Organelles and structures, thereby linking various stages of Biosynthesis to Ribosomes, The Nucleus, and Mitochondria.

In the 1930s–1950s, a new direction emerged in Cytology—physicochemical and biochemical cytology—aimed at studying the PHYSICOCHEMICAL PROPERTIES OF the cell and the biochemical processes occurring within it. This is reflected in the works of R. Chambers, J. Loeb, F. Weber, N. Koltsov, B. Kedrovsky, A. Shabadash, and others. These studies followed their own "internal logic," with protoplasm being investigated as the substrate of vital phenomena. These and subsequent studies are closely intertwined with cell biochemistry, particularly The properties of cellular Proteins. In the second half of the XX century, the problems of differentiation and determination gained particular prominence in cytology. Eventually, all these processes and their molecular mechanisms branched out from traditional cytology into cell biology (1940–1950). Its core focus became the study of general biological questions at the microscopic, macromolecular, and molecular levels.