Protoplasm (; ) is the part of a cell that is surrounded by a

plasma 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 extr ...

. 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 The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

(e.g., Mohl, 1846), but for others, it also includes the

nucleoplasm The nucleoplasm, also known as karyoplasm, is the type of protoplasm that makes up the cell nucleus, the most prominent organelle of the eukaryotic cell. It is enclosed by the nuclear envelope, also known as the nuclear membrane. The nucleoplasm r ...

(e.g., Strasburger, 1882). For Sharp (1921), "According to the older usage the extra-nuclear portion of the

protoplast Protoplast (), is a biology, biological term coined by Johannes von Hanstein, Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterium, bacterial, or f ...

'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

Kölliker (1863), originally as synonym for protoplasm''">Albert_von_Kölliker.html" ;"title="'coined by Albert von Kölliker">Kölliker (1863), originally as synonym for protoplasm''and

van Beneden (1875), or 'term coined by Edouard Van Beneden">van Beneden (1875), or karyoplasm, used by Walther Flemming">Flemming (1878)''">karyoplasm">'term coined by Edouard Van Beneden">van Beneden (1875), or karyoplasm, used by Walther Flemming">Flemming (1878)''" The cytoplasm definition of Strasburger excluded the plastids (''Chromatoplasm''). Like the nucleus, whether to include the

vacuole A vacuole () is a membrane-bound organelle which is present in Plant cell, plant and Fungus, fungal Cell (biology), cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water ...

in the protoplasm concept is controversial.

Terminology

Besides "protoplasm", many other related terms and distinctions were used for the cell contents over time. These were as follows:Battaglia, E. (1985)
Meiosis and mitosis: a terminological criticism
''Annali di Botanica'' (Rome) 43: 101–140. (Table 3, "-plasma derivatives", p. 118). * '' Urschleim'' ( Oken, 1802, 1809), * ''Protoplasma'' (Purkinje, 1840, von Mohl, 1846), * ''Primordialschlauch'' (primordial utricle, von Mohl, 1846), * '' sarcode'' (

Dujardin Dujardin is a French surname, meaning "from the garden", and may refer to: * Charlotte Dujardin (born 1985), British dressage rider * Édouard Dujardin (1861–1949), French writer * Félix Dujardin (1801–1860), French biologist * Jean Dujar ...

, 1835, 1841), * ''

Cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

a'' ( Kölliker, 1863), * ''Hautschicht/Körnerschicht'' ( ectoplasm/

endoplasm Endoplasm, also known as entoplasm, generally refers to the inner (often granulated), dense part of a cell's cytoplasm. This is opposed to the ectoplasm (cell biology), ectoplasm which is the outer (non-granulated) layer of the cytoplasm, which ...

, Pringsheim, 1854; Hofmeister, 1867),Wayne (2009), p. 134. * ''Grundsubstanz'' (

ground substance Ground substance is an amorphous gel-like substance in the extracellular space of animals that contains all components of the extracellular matrix (ECM) except for fibrous materials such as collagen and elastin. Ground substance is active in the d ...

, Cienkowski, 1863), *

metaplasm A metaplasm is almost any kind of alteration, whether intentional or unintentional, in the pronunciation or the orthography of a word. The change may be phonetic only, such as pronouncing ''Mississippi'' as ''Missippi'' in English, or acceptance ...

/protoplasm (Hanstein, 1868), * deutoplasm/protoplasm (van Beneden, 1870), * bioplasm (Beale, 1872), * paraplasm/protoplasm (Kupffer, 1875), * inter-filar substance theory (Velten, 1876) * '' Hyaloplasma'' (Pfeffer, 1877), * ''

Protoplast Protoplast (), is a biology, biological term coined by Johannes von Hanstein, Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterium, bacterial, or f ...

'' (Hanstein, 1880), * ''Enchylema/Hyaloplasma'' (Hanstein, 1880), * ''Kleinkörperchen'' or ''Mikrosomen'' (small bodies or microsomes, Hanstein, 1882), * paramitome (Flemming, 1882), * '' Idioplasma'' (Nageli, 1884), * ''Zwischensubstanz'' (inter-alveolar substance, Bütschli, 1892), * ''Grundplasma'' (ground plasma, Schütt, 1895), * '' ergastoplasme'' (Garnier, 1897), * phaneroplasm/cryptoplasm (Seifriz, 1931), * cytoplasmic matrix (Munson, 1899; ''zytoplasmatische Matrix'', Bergmann, 1956), * ''Protoplasma- oder Zelleinschlüsse'' (protoplasmic or cellular inclusions, Szymonowicz, 1901), * kinoplasm/trophoplasm (Strasburger et at., 1912), *

cytosol The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells ( intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondri ...

(Lardy, 1965).

History

The word "protoplasm" comes from the Greek ''protos'' for ''first'', and ''plasma'' for ''thing formed'', and was originally used in religious contexts. It was used in 1839 by J. E. Purkinje for the material of the animal embryo.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. 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 A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, ...

and the cell sap (''Zellsaft'') within the

.von Mohl, H. 1846
Ueber die Saftbewegung im Inneren der Zellen
''Bot. Ztg.'' 4: 73-78, 89-94. Max Schultze in 1861 proposed the "Protoplasm Doctrine" which states that ''all living cells are made of a living substance called Protoplasm''. 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. The protoplasm became an " epistemic thing". Its composition, however, was mysterious and there was much controversy over what sort of substance it was. In 1872, Beale created the

vitalist Vitalism is a belief that starts from the premise that "living organisms are fundamentally different from non-living entities because they contain some non-physical element or are governed by different principles than are inanimate things." Wher ...

term "bioplasm", to contrast with the

materialism Materialism is a form of monism, philosophical monism according to which matter is the fundamental Substance theory, substance in nature, and all things, including mind, mental states and consciousness, are results of material interactions. Acco ...

of Huxley.Beale, L. S. (1872).
Bioplasm
'. London: J. & A. Churchill. In 1880, term

was proposed by Hanstein (1880) for the entire cell, excluding the cell wall, and some authors like Julius von Sachs (1882) preferred that name instead of cell.Wayne (2009), p. 15. In 1965, Lardy introduced the term "

", later redefined to refer to the liquid inside cells.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

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 vitalism, vitalistic theory of life. Attempts to investigate the

origin of life Abiogenesis is the natural process by which life arises from abiotic component, non-living matter, such as simple organic compounds. The prevailing scientific hypothesis is that the transition from non-living to organism, living entities on ...

through the creation of synthetic "protoplasm" in the laboratory were not successful. The idea that protoplasm of eukaryotes is simply divisible into a ground substance called "cytoplasm" and a structural body called the

cell nucleus The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryote, eukaryotic cell (biology), cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have #Anucleated_cells, ...

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. Today, it is known that the cell contents are structurally very complex and contain multiple

organelle In cell biology, an organelle is a specialized subunit, usually within a cell (biology), cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as Organ (anatomy), organs are to th ...

s, 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 In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable light scattering by particles, scattering of light. On a macroscopic scale ...

granular Granularity (also called graininess) is the degree to which a material or system is composed of distinction (philosophy), distinguishable pieces, granular material, "granules" or grain, "grains" (metaphorically). It can either refer to the exten ...

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. In

eukaryote The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...

s, the portion of protoplasm surrounding the

is known as the

and the portion inside the nucleus as the

. In

prokaryote A prokaryote (; less commonly spelled procaryote) is a unicellular organism, single-celled organism whose cell (biology), cell lacks a cell nucleus, nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Ancient Gree ...

s the material inside the plasma membrane is the bacterial cytoplasm, while in

Gram-negative bacteria Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the Crystal violet, crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelo ...

the region outside the plasma membrane but inside the outer membrane is the periplasm.

Chemical composition

There are about 30 elements, like

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

, sulphur,

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

and many others which are identified in protoplasm of different cells. They form compounds, like

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

(65-80%),

carbohydrates A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ma ...

ions An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, re ...

lipids Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins Vitamin A, A, Vitamin D, D, Vitamin E, E and Vitamin K, K), monoglycerides, diglycerides, phospholipids, and others. The fu ...

nucleic acids Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic a ...

(

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

and

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

fatty acids In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...

glycerol Glycerol () is a simple triol compound. It is a colorless, odorless, sweet-tasting, viscous liquid. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pha ...

nucleotides Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both o ...

nucleosides Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide ...

and

minerals In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): M ...

. 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.

Functions

Some functions of protoplasm are: # It provides place where all life functions occur # The cells respond to various stimuli like temperature, light, chemicals, gravitation, pricking, electric shocks and others because of properties of protoplasm. # Cyclosis (the streaming movement of protoplasm is known as Cyclosis. It helps in even distribution of various materials in the cells.)

References

External links

* {{Authority control Cell biology 1839 introductions