The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
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The ectoplasm is a clear region of the cytoplasm just under the cellular or plasma membrane from which all cellular organelles and macromolecules visible in the light microscope have been excluded. This is most easily seen in amoeba and other protozoans that lack a thick cell wall and are thin enough to observe in a live mount. The origin of the ectoplasm is the sol-gel transformation responsible for cytoplasmic streaming. Elements of the cytoskeleton such as microtubules and microfilaments polymerize along the cell periphery and change a portion of the cytoplasm into the gel state. Contraction of this gel creates hydrostatic pressure that causes streaming of the soluble regions of the cytoplasm (also known as the endoplasm).This hydrostatic pressure also causes some of the aqueous fluid of the cytoplasm to squeeze through the gel and to accumulate under the plasma membrane. As the fluid passes through the tight network of filaments in the gel, all macromolecules and organelles are filtered out leaving only the clear, watery solution known as ectoplasm.
This phenomenon is not of much physiological importance. Probably the most important reason for retaining the distinction between ectoplasm and endoplasm is that the later is the location of the endoplasmic reticulum, an important membranous network responsible for protein and lipid synthesis, metabolism of many toxic compounds, and a host of other vital processes.