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1. The living contents of a cell that is surrounded by a plasma membrane. It is a general term for the cytoplasm. Protoplasm is composed of a mixture of small molecules such as ions, amino acids, monosaccharides and water, and macromolecules such as nucleic acids, proteins, lipids and polysaccharides. In eukaryotes, the protoplasm surrounding the cell nucleus is known as the cytoplasm and that 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. (

2. The entire contents of a cell comprising the nucleus and the cytoplasm. It is a semi-fluid, transparent substance which is the living matter of plant and animal cells. (

3. The fluid living content of the cell that consists of two major divisions, the cytoplasm and the nucleoplasm (cell nucleus). It is composed mainly of nucleic acids, proteins, lipids, carbohydrates, and inorganic salts. (

4. The organized colloidal complex of organic and inorganic substances (as proteins and water) that constitutes the living nucleus, cytoplasm, plastids, and mitochondria of the cell. (

5. The colorless material comprising the living part of a cell, including the cytoplasm, nucleus, and other organelles. (Google Dictionary)

Word origin: From German Protoplasma (1846), used by German botanist Hugo von Mohl (1805-1872), on notion of “first-formed,” from Greek proto– “first” + plasma “something molded.”

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