(protistology) Endoplasm; endosarc; endoplasta; the inner granulated layer of the cytoplasm of certain unicellular organisms, e.g. amoeba
(embryology) The inner granulated layer of the protoplasm, esp. of a developing ovum
In protistology, the entoplasm refers to the inner granulated layer of the cytoplasm of certain unicellular organisms such as amoeba. The amoeba cell's cytoplasm in particular may be divided into two layers: the entoplasm and the ectoplasm. The entoplasm, more known as endoplasm, is the inner part of the cytoplasm. It is dense and granulated as opposed to the outer part of the cytoplasm, the ectoplasm (which is non-granulated and transparent). The entoplasm is adjacent to the nucleus and is separated from the nucleus by the nuclear envelope. Apart from granules, it may also contain water, inorganic ions, carbohydrates, lipids, enzymes, amino acids, nucleic acids, etc. It also houses the endomembrane system. Thus, it is metabolically active, i.e. involved in various metabolic processes, e.g. cell respiration, protein synthesis, and cell division. The varying consistencies of the entoplasm and ectoplasm are useful in the formation of pseudopods, which are involved in locomotion.
Word origin: Greek ento- (within) + Greek -plasm(a) (that which has form)