History of Cell Theory Antonie van Leeuwenhoek observed

History of Cell Theory

Antonie van Leeuwenhoek - observed little “animalcules” - studied living cells - together with Hooke, began the study of cells = CYTOLOGY Robert Hooke (1665) - saw tiny, empty compartments in cork - called them “cellulae” (Latin for “small room”) - they were actually walls of dead cells

History of Cell Theory Robert Brown (1820 s) - a botanist - observed a sphere-like structure in every plant cell he examined - called the structure a “nucleus” Theodor Schwann and Matthias Schleiden (1830 s) - a zoologist and a botanist - together proposed that each cell develops as an independent unit Rudolf Virchow and Robert Remak (1855) - concluded that every cell originated from the division of another cell

Cell Theory 1. 2. 3. All living things are made up of cells. The cell is the basic structural and functional unit of life. All cells arise from pre-existing cells.

Cells • • • Micrometres (μm) are used to measure cells 1 μm = 1 x 10 -6 m or 0. 000001 m Cells range in size about 1 μm and 100 μm How big is the “largest” cell? Nutrients (for energy) are taken into the cell and waste products are removed from the cell via the semipermeable plasma membrane [video]. Cells maximize their surface area while minimizing their volumes so that nutrients and waste products do not have to travel far.