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Two experiments in 1924 laid the groundwork to fill in this gap. By measuring the capacitance of erythrocyte solutions Fricke determined that the cell membrane was 3.3 nm thick. [7] Although the results of this experiment were accurate, Fricke misinterpreted the data to mean that the cell membrane is a single molecular layer.
[13] [14] Hooke coined the term "cell", suggesting a resemblance between plant structures and honeycomb cells. [137] The hand-crafted, leather-and-gold-tooled microscope he designed and used to make the observations for Micrographia , which Christopher Cock made for him in London, is on display at the National Museum of Health and Medicine in ...
Hooke most famously describes a fly's eye and a plant cell (where he coined that term because plant cells, which are walled, reminded him of the cells in a honeycomb [2]). Known for its spectacular copperplate of the miniature world, particularly its fold-out plates of insects, the text itself reinforces the tremendous power of the new microscope.
The cell membrane, or plasma membrane, is a selectively permeable [citation needed] biological membrane that surrounds the cytoplasm of a cell. In animals, the plasma membrane is the outer boundary of the cell, while in plants and prokaryotes it is usually covered by a cell wall .
The cell was first discovered by Robert Hooke in 1665 using a microscope. The first cell theory is credited to the work of Theodor Schwann and Matthias Jakob Schleiden in the 1830s. In this theory the internal contents of cells were called protoplasm and described as a jelly-like substance, sometimes called living jelly.
Robert Hooke's microscope which he described in the 1665 Micrographia: he coined the biological use of the term cell In the first half of the 18th century, botany was beginning to move beyond descriptive science into experimental science.
1665: Robert Hooke publishes Micrographia, a collection of biological drawings. He coins the word cell for the structures he discovers in cork bark. 1674: Antonie van Leeuwenhoek improves on a simple microscope for viewing biological specimens (see Van Leeuwenhoek's microscopes).
Illustration of a eukaryotic cell membrane Comparison of a eukaryotic vs. a prokaryotic cell membrane. The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space).