Introduction of cell biology. Lecture 1
Early History of the Microscope
• Compound Microscope (the double lens)
•examined a cork from a tree and saw its cell, seeing the honey combs
•called the honeycomb pores CELLS, but really saw empty cell walls of a dead plant
•Discovery of cell usually generated to him
Anton Van Leeuwenhoek
• for 50 years sent letters to the royal society about his microscopic findings in London
• was the first to examine a drop of pond water under a microscope
• Observed ANIMALCULES (they darted back and forth under the microscope)
•single lens, The BICONVEX LENS, magnifying 270 times.
Matthias schleiden (1838-Botanist) =believed that even though there are distinctive tissues, Plants consisted of cells and that it
arose from a single cell
Theodor Schwann (colleague of Schleiden and a German Zoologist, 1839) = published a report stating that cells of plants and
animals are the same in structure and came up the 2THEORIES
All organisms have one or more cells
Cells are the structural unit of life (they make up a tissue then an organ then the human being)
Rudolf Virchow (1855) = German Pathologist, came up with the third cell theory (tenant)
Cells arrive or become through division of pre-existing cells.
Basic Properties of All Cells.
Cells are highly Complex:
•Order and consistency (like a machine or military)
•The more complex, the greater the number of parts that HAS to be in its right place
• more regulated (Controlled) to maintain the system, Less tolerance for error
•e.g.: DNA duplication = error (1 in 10 million), quickly corrected by repair mechanisms.
•Complex and organized
•each type of cell has a specific consistent appearance/particular shape and position
note that chemical processes such as protein synthesis are similar in all living organisms
Cells possess Genetic program and the means to use it
•There is specific information that is encoded from a
collection of genes to make organisms.
• There are TONS of information (zillions) and they are packaged
away into set of chromosomes.
•Genes = blueprints
= the director of what goes on in the cell
Because of the Genes molecular structure, this can allow the