Протоплазма: Цитоплазма мен ядроплазманың жалпы аталымы

Alternative term for cytoplasm or cytoplasm and nucleoplasm

Protoplasm ('/p//r//oʊ//t//ə/,/p//l//æ//z//əm/; ) is the living 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), 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)]." The cytoplasm definition of Strasburger excluded the plastids (Chromatoplasm). Like the nucleus, whether to include the vacuole in the protoplasm concept is controversial.

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. 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.

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.