The amoeba is a relatively simple single-celled organism. Its internal structure consists of a few organelles that enable it to carry out all functions necessary for life in an aquatic environment. It is separated from its environment by a cellular membrane that usually includes a cell coat. The structure of the cell coat varies depending upon the species.
A specific genus of amoeba, Paradermamoeba, has been found to have an exceptionally thick and strong cell coat. The structure of this cell coat has been difficult to determine due to its relative impermeability. Only after partial digestion of the cell coat was it able to be properly visualized using an electron microscope, suggesting the cell coat is impenetrable to light.
The structure of the cell coat of Paradermamoeba is likely what gives it its strength and flexibility. The cell coat includes a network of regularly spaced, tightly packed, helical protrusions that have hollow, pentagonal, glass-shaped tips on their ends. It is believed that this is the structure that provides the amoeba with its impenetrable quality.
This summary was contributed by Alexis Dean.Edit Summary
"The cell coat of this species is about 520 nm of total thickness, and consists of a layer of regularly arranged tightly packed helical-shaped glycostyles. Coils of neighboring helices overlap. Each glycostyle terminates with a hollow straight funnel-shaped structure, which sometimes seems to be pentagonal in cross-section. The length of the spiral part of the glycostyles is about 400 nm and the diameter is about 100 nm; length of the straight terminal part of glycostyles is about 120 nm. Helices form 7-7,5 turns. They are embedded in an unstructured electron-transparent matrix which does not seem to prevent the neighboring glycostyles from moving in relation to each other." (Smirnov and Goodkov 1993:1)
[Note: The "impenetrability" appears to refer to the inability to determine the structure of the organism by using electron microscopy, which uses a beam of electrons to illuminate it.]