Protoplasm

Protoplasm (Template:IPAc-en;<ref>Template:Cite dictionary</ref><ref>Template:Cite Dictionary.com</ref> Template:Plural form)<ref>Template:Wiktionary-inline</ref> is the part of a cell that is surrounded by a plasma membrane. It is a mixture of small molecules such as ions, monosaccharides, amino acids, and macromolecules such as proteins, polysaccharides, lipids, etc.

In some definitions, it is a general term for the cytoplasm (e.g., Mohl, 1846),<ref name="Cammack">Template:Citation</ref> but for others, it also includes the nucleoplasm (e.g., Strasburger, 1882). For Sharp (1921), "According to the older usage the extra-nuclear portion of the protoplast [the entire cell, excluding the cell wall] was called "protoplasm," but the nucleus also is composed of protoplasm, or living substance in its broader sense. The current consensus is to avoid this ambiguity by employing Strasburger's (1882) terms cytoplasm [coined by Kölliker (1863), originally as synonym for protoplasm] and nucleoplasm [term coined by van Beneden (1875), or karyoplasm, used by Flemming (1878)]."<ref>Sharp, L. W. (1921). Introduction To Cytology. New York: McGraw Hill, p. 25.</ref><ref>Strasburger, E. (1882). Ueber den Theilungsvorgang der Zellkerne und das Verhältnis der Kernteilung zur Zellteilung. Arch Mikr Anat, 21: 476-590, BHL.</ref><ref>Beneden, E. van (1875). La maturation de l'oeuf, la fécondation et les premières de développement embryonnaire des Mammiferes d'après les recherches faites chez le lapin. Bull. Acad. Bel. Cl. Sci. 40, 2 sèr.: 686-736, BHL.</ref><ref>Flemming, W. (1878). Beiträge zur Kenntniss der Zelle und ihrer Lebenserscheinungen. Arch. f. mikr. Anat., 16: 302-436, p. 360, BHL.</ref><ref>Battaglia, E. (2009). Caryoneme alternative to chromosome and a new caryological nomenclature. Caryologia, 62(4), 1.</ref> The cytoplasm definition of Strasburger excluded the plastids (Chromatoplasm).

Like the nucleus, whether to include the vacuole in the protoplasm concept is controversial.<ref>Parker, J. 1972. Protoplasmic resistance to water deficits, p. 125-176. In: Kozlowski, T. T. (ed.), Water deficits and plant growth. Vol. III. Plant responses and control of water balance. Academic Press, New York, p. 144, [1].</ref>

Terminology

Besides "protoplasm", many other related terms and distinctions were used for the cell contents over time. These were as follows:<ref>Sharp (1921), p. 11, 32-34.</ref><ref name=battaglia>Battaglia, E. (1985). Meiosis and mitosis: a terminological criticism. Annali di Botanica (Rome) 43: 101–140. (Table 3, "-plasma derivatives", p. 118).</ref>

• Urschleim (Oken, 1802, 1809),<ref>Grundriss der Naturphilosophie.</ref><ref>Lehrbuch der Naturphilosophie.</ref>
• Protoplasma (Purkinje, 1840, von Mohl, 1846),<ref name=purkinje/><ref name=Mohl/>
• Primordialschlauch (primordial utricle, von Mohl, 1846),<ref name=Mohl/>
• sarcode (Dujardin, 1835, 1841),<ref>Dujardin, F. 1835. Recherches sur les organisms inférieurs. Annales des Sciences Naturelles 4: 343–377, [2].</ref><ref>Dujardin, F. (1841). Histoire Naturelle des Zoophytes Infusoires. Paris: Librarie Encyclopedique de Roret. p. 26.</ref>
• Cytoplasma (Kölliker, 1863),<ref>Kölliker, R. A. v. (1863). Handbuch der Gewebelehre des Menschen. 4. Auflage. Leipzig: Wilhelm Engelmann.</ref>
• Hautschicht/Körnerschicht (ectoplasm/endoplasm, Pringsheim, 1854; Hofmeister, 1867),<ref name="Wayne 2009, p. 134">Wayne (2009), p. 134.</ref><ref>Vines, S. H. (1877). An account of Prof. Strasburger's observation on protoplasm. Quart. J. Micr. Sc., Lond., 1877, n. s., 17, pp. 124-132. link.</ref>
• Grundsubstanz (ground substance, Cienkowski, 1863),<ref>Cienkowski, L. 1863. Zur Entwicklungsgeschichte der Myxomyceten. Jahrb. Wiss. Bot. 3: 325-337, [3].</ref>
• metaplasm/protoplasm (Hanstein, 1868),<ref name="Wayne 2009, p. 134"/>
• deutoplasm/protoplasm (van Beneden, 1870),<ref>Van Beneden, E. Recherches sur la composition et la signification de l'œuf. F. Hayez, Bruxelles, 1870 (Extrait du tome XXXIV des Mém. cour. des savants étrangers, publiés par l'Académie royale des sciences, des lettres et des beaux-arts de Belgique). link.</ref>
• bioplasm (Beale, 1872),<ref name=beale/>
• paraplasm/protoplasm (Kupffer, 1875),<ref>Kupffer, K. W. 1875. Ueber Differenzierung des Protoplasmas an den Zellen tierischer Gewebe. Schriften des Naturwissenschaft, Vereins für Schleswig-Holstein, 1 (3), 229-242, link.</ref>
• inter-filar substance theory (Velten, 1876)<ref>Velten, W. 1876. Die physikalische Beschaffenhoit des pflanzlichon Protoplasmas. Sitzber. Akad. Wiss. Wien, Math.-Nat. Kl., 73: I 131-151, [4].</ref>
• Hyaloplasma (Pfeffer, 1877),<ref>Pfeffer, W. Osmotische Untersuchungen. W. Engelmann, Leipzig. link.</ref>
• Protoplast (Hanstein, 1880),<ref>Hanstein (1880), p. 45.</ref>
• Enchylema/Hyaloplasma (Hanstein, 1880),<ref>Hanstein (1880), pp. 24, 39.</ref>
• Kleinkörperchen or Mikrosomen (small bodies or microsomes, Hanstein, 1882),<ref name="Wayne 2009, p. 134"/>
• paramitome (Flemming, 1882),<ref>Flemming, W. (1882). Zellsubstanz, Kern, und Zelltheilung. Vogel, Leipzig, [5].</ref>
• Idioplasma (Nageli, 1884),<ref name=battaglia/>
• Zwischensubstanz (inter-alveolar substance, Bütschli, 1892),<ref>Bütschli, O. 1892. Untersuchungen über mikroskopische Schäume und das Protoplasma. Leipzig, [6].</ref>
• Grundplasma (ground plasma, Schütt, 1895),<ref>Schütt, F. (1895). Die Peridineen der Plankton Expedition. Ergebnisse der Plankton-Expedition des Humbold-Stiftung, Bd IV, p. 1–27, Lipsius & Tischer, Kiel. link.</ref>
• ergastoplasme (Garnier, 1897),<ref name=battaglia/>
• phaneroplasm/cryptoplasm (Seifriz, 1931),<ref>Seifriz, W. (1931). The structure of protoplasm. Science 73, 648-649. link.</ref>
• cytoplasmic matrix (Munson, 1899; zytoplasmatische Matrix, Bergmann, 1956),<ref>Munson, J. P., 1899 The Ovarian Egg of Limulus. Athenaeum Press, Boston, Massachusetts</ref><ref>Bargmann, W. (1956). Über einige Probleme und Ergebnisse des elektronen-mikroskopischen Studiums der Zelle. Dtsch. med. Wschr. 81 (28): 1109-1125.</ref>
• Protoplasma- oder Zelleinschlüsse (protoplasmic or cellular inclusions, Szymonowicz, 1901),<ref>Szymonowicz, L. (1901). Lehrbuch der Histologie und der mikroskopischen Anatomie. Stuber, Würzburg. link.</ref><ref>Szymonowicz, L. (1902). Textbook of histology and microscopic anatomy of the human body, including microscopic technique. Philadelphia, Lea Bros. link.</ref>
• kinoplasm/trophoplasm (Strasburger et at., 1912),<ref name="Wayne 2009, p. 134"/>
• cytosol (Lardy, 1965).<ref name=lardy/>

History

The word "protoplasm" comes from the Greek protos for first, and plasma for thing formed, and was originally used in religious contexts.<ref>Wayne, R. 2009. Plant Cell Biology: From Astronomy to Zoology. Amsterdam: Elsevier/Academic Press, p. 133.</ref> It was used in 1839 by J. E. Purkinje for the material of the animal embryo.<ref name=purkinje>Purkinje J.E. 1840. Über die Analogien in den Strukturelementen des thierischen und pflanzichen Organismus. In: Übersicht der Arbeiten und Veränderungen der schlesischen Gesellschaft für vaterländische Kultur, Jahre 1839: 81.</ref><ref>Bynum, W. F., Browne, E. J. & Porter, R. (1981). Dictionary of the history of science. Princeton University Press.</ref> Later, in 1846 Hugo von Mohl redefined the term (also named as Primordialschlauch, "primordial utricle") to refer to the "tough, slimy, granular, semi-fluid" substance within plant cells, to distinguish this from the cell wall and the cell sap (Zellsaft) within the vacuole.<ref name=Mohl>von Mohl, H. 1846. Ueber die Saftbewegung im Inneren der Zellen. Bot. Ztg. 4: 73-78, 89-94.</ref><ref>Larson, P. R. (1994). The Vascular Cambium: Development and Structure. Springer-Verlag: New York and Berlin, p. 30-31, [7].</ref><ref>Evert, R. F. 2006. Esau's Plant Anatomy: Meristems, Cells, and Tissues of the Plant Body: Their Structure, Function, and Development. 3rd.ed. John Wiley & Sons, Inc: Hoboken, New.Jersey, p. 16, [8].</ref> Max Schultze in 1861 proposed the "Protoplasm Doctrine" which states that all living cells are made of a living substance called Protoplasm.<ref name=":0">Template:Cite book</ref> Thomas Huxley (1869) later referred to it as the "physical basis of life" and considered that the property of life resulted from the distribution of molecules within this substance.<ref>Huxley, T. H. 1869. The Physical Basis of Life. New Haven, Conn., The College Courant.</ref> The protoplasm became an "epistemic thing".<ref>Brain, R.M. "Protoplasmania: Huxley, Haeckel, and the Vibratory Organism in Fin de Siècle Visual Cultures", in The Art of Evolution: Darwin, Darwinisms, and Visual Cultures, F. Brauer and Larson, B. University Presses of New England, 2009, pp. 92-123, [9].</ref> Its composition, however, was mysterious and there was much controversy over what sort of substance it was.<ref name="Harvey2004">Template:Citation</ref>

In 1872, Beale created the vitalist term "bioplasm", to contrast with the materialism of Huxley.<ref name=beale>Beale, L. S. (1872). Bioplasm. London: J. & A. Churchill.</ref><ref>Bynum et al. (1981), p. 344.</ref> In 1880, term protoplast was proposed by Hanstein (1880) for the entire cell, excluding the cell wall,<ref>Hanstein, J. (1880). Das Protoplasma. Heidelberg.</ref><ref>Sharp (1921), p. 24.</ref> and some authors like Julius von Sachs (1882) preferred that name instead of cell.<ref>Wayne (2009), p. 15.</ref>

In 1965, Lardy introduced the term "cytosol", later redefined to refer to the liquid inside cells.<ref name=lardy>Lardy, H. A. 1965. On the direction of pyridine nucleotide oxidation-reduction reactions in gluconeogenesis and lipogenesis. In: Control of energy metabolism, edited by B. Chance, R. Estabrook, and J. R. Williamson. New York: Academic, 1965, p. 245, [10].</ref>

By the time Huxley wrote, a long-standing debate was largely settled over the fundamental unit of life: was it the cell or was it protoplasm? By the late 1860s, the debate was largely settled in favor of protoplasm. The cell was a container for protoplasm, the fundamental and universal material substance of life. Huxley's principal contribution was to establish protoplasm as incompatible with a vitalistic theory of life.<ref name="Geison1969">Template:Citation</ref> Attempts to investigate the origin of life through the creation of synthetic "protoplasm" in the laboratory were not successful.<ref name="Lazcano2008">Template:Citation</ref>

The idea that protoplasm of eukaryotes is simply divisible into a ground substance called "cytoplasm" and a structural body called the cell nucleus reflects the more primitive knowledge of cell structure that preceded the development of electron microscopy, when it seemed that cytoplasm was a homogeneous fluid and the existence of most sub-cellular compartments, or how cells maintain their shape, was unknown.<ref name="Satir2004">Template:Citation</ref> Today, it is known that the cell contents are structurally very complex and contain multiple organelles, the cytoskeleton and biomolecular condensates.the word protoplasm is mainly divided in to two parts cytoplasm and nucleus.

Description

Physical nature

Protoplasm is physically translucent, granular slimy, semifluid or viscous. In it, granules of different shapes and sizes are suspended in solution. It may exist in two interchangeable states which are more liquid-like sol state and more solid-like gel state which is like jelly. The constituent molecules are free to move in sol state, while in gel state, the constituent molecules are compactly arranged. Protoplasm becomes opaque when it is heated. It also coagulates on heating. It occurs everywhere in the cell.<ref name=":0" /> In eukaryotes, the portion of protoplasm surrounding the cell nucleus is known as the cytoplasm and the portion inside the nucleus as the nucleoplasm. In prokaryotes the material inside the plasma membrane is the bacterial cytoplasm, while in Gram-negative bacteria the region outside the plasma membrane but inside the outer membrane is the periplasm.<ref name="Cammack" />

Chemical composition

There are about 30 elements, like carbon, hydrogen, oxygen, phosphorus, sulphur, calcium and many others which are identified in protoplasm of different cells. They form compounds, like water (65-80%), carbohydrates, ions, proteins, lipids, nucleic acids (DNA and RNA), fatty acids, glycerol, nucleotides, nucleosides and minerals. They are living as long as they are part of protoplasm. They are not able to perform functions of life independently. The composition of protoplasm is inconsistent and continuous changes take place in it.<ref name=":0" />

Functions

Some functions of protoplasm are:

1. It provides place where all life functions occur
2. The cells respond to various stimuli like temperature, light, chemicals, gravitation, pricking, electric shocks and others because of properties of protoplasm.
3. Cyclosis (the streaming movement of protoplasm is known as Cyclosis. It helps in even distribution of various materials in the cells.)<ref name=":0" />

See also

• Chemical evolution
• Membrane
• Symplast

External links

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