Dictionary > Ectoplasm

Ectoplasm

Definition
noun, plural: ectoplasms
The outer, non-granulated, clear portion of the cytoplasm of a cell
Supplement
The cytoplasm of certain species may be divided into endoplasm and ectoplasm. The inner dense part of the cytoplasm, and often granulated, is the endoplasm. The clear outer portion of the cytoplasm is the ectoplasm. While the endoplasm is adjacent to the nuclear envelope the ectoplasm lies immediately to the plasma membrane. Thus, the endoplasm houses the endomembrane system, which makes the endoplasm metabolically active. The ectoplasm, in turn, contains large numbers of actin filaments, and as such is associated with providing an elastic support for the cell membrane.1
In certain organisms such as amoeba, the ectoplasm is the thin, transparent, somewhat rigid, contractile portion of the cytoplasm. The differing consistencies of endoplasm and ectoplasm aid in the formation of pseudopods. Another function of ectoplasm in certain amoebae is for food ingestion. When the food comes in contact of an amoeba cell, the ectoplasm forms a tube called ectoplasmic tube, takes the food into it, and then converted into a food vacuole.2
In certain ciliates, the basal plates from where the cilia arise are embedded in the ectoplasm. In Paramecium, for instance, the ectoplasm contains the infraciliary system (as well as trichocysts).2
Word origin: Greek ekto(s)– (outside) + Greek -plasm(a) (that which has form)
Synonym(s):

  • exoplasm

Compare:

  • endoplasm
  • See also:

    Related term(s):

  • Sol gel transformation
  • Recruitment zone
  • Reference(s):

    1 Guyton, A. C. & Hall, J. E. Textbook of Medical Physiology, Eleventh Edition. Saunders.

    2 Biosystematics, Structure and Functions of Invertebrates. Retrieved from http://assets.vmou.ac.in/MZO01.pdf.


    You will also like...

    Ecosystem Succession
    Ecosystem Succession

    If the balance of nature is left untouched, landscapes can change dramatically over time. A previous ecosystem is supers..

    An artist's depiction of the origin of amphibians
    Amphibians & Early Reptiles

    Obtaining air outside an aquatic environment required species to acquire suitable adaptations, and this was the case of ..

    Freshwater Ecology
    Freshwater Ecology

    Freshwater ecology focuses on the relations of aquatic organisms to their freshwater habitats. There are two forms of co..

    DNA - schematic
    Genetic Mutations

    This tutorial looks at the mutation at the gene level and the harm it may bring. Learn about single nucleotide polymorph..

    Adaptive Radiation
    Adaptive Radiation

    The diversification of several new species from a recent ancestral source, each adapted to utilize or occupy a vacant ad..

    Young plant growing from the soil.
    Soils

    Nutrients in the soil are essential to the proper growth of a land plant. This tutorial deals with the properties of soi..