For an explanation, see the main splats page
SPLATS about cells and tissues
The principles of cells and tissues
- The cell is the basis of all living things, but cells are made up of smaller parts with different functions. Only a cell can make another cell.
- In 1663, Robert Hooke was able to see and describe plant cells, seen in a thin slice of cork, examined under the microscope, and he estimated their size.
- Hooke's estimate: in one inch, "near eleven hundred of them . . . in a Cubick Inch, above twelve hundred Millions, or 1 259 712 000, a thing most incredible".
- René Joachim Henri Dutrochet was probably the first to offer us the theory that all living things are composed of cells, rather than Schleiden or Schwann.
- In 1858, Rudolf Virchow ruled out spontaneous generation, saying that all cells arise from pre-existing cells, saying it in Latin: "Omnis cellula e cellula".
- In 1860, Louis Pasteur stated his view that all living things come from living things, which he expressed in Latin, saying: "Omne vivum e vivo".
- All the procaryotes have regions within them which are locally different, but they have no membrane-bound organelles inside the outer membrane.
- The life forms we call procaryotes may also be considered as acellular, in that they contain a whole organism in a single container, rather than unicellular.
- Saying that a cell is filled with cytoplasm is about as useful as saying a television set is filled with teleplasm: neither statement contains any information.
- A cell membrane is a complex structure that interacts with the cells' contents and surroundings to play a major part in the operation of the cell.
- The cell membrane is more than a bag: it is an important part of the cell which plays a major role in deciding what is, and is not, allowed into the cell.
- Cells may take up material by active transport, where parts of the membrane select particular molecules and carry them into (or out of) the cell.
- Cells may take up material by pinocytosis, where the cell membrane puckers in, surrounds a particle or some fluid, seals it off, and then releases it inside.
- All of the organisms we call eucaryotes have membrane-bound organelles, including the nucleus, lysosomes, endoplasmic reticulum, Golgi bodies and mitochondria.
- Serial endosymbiosis theory says the parts of eucaryotic cells were once separate simple organisms which linked together to form a complex organism.
- In 1914, Warren H. Lewis and his wife, Margaret Lewis, used bright field microscopy to be the first to describe mitochondria and mitochondrial shape changes.
- The role of the mitochondria is to generate energy in the cell, so the mitochondria are the centres where respiration is used to generate ATP from ADP.
- The nucleus of a eucaryotic cell is visible under the light microscope, especially when it is treated with a DNA-specific dye that stains the chromosomes.
- In 1956, Henry Borsook and Paul Charles Zamecnik established that the ribosomes of the endoplasmic reticulum were the site of protein synthesis.
- The role of the ribosomes is to make protein as specified in accordance with the universal genetic code by the sequence of bases on a strand of messenger RNA
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