Cell Coat Provides Impermeability

Biological Strategy

AskNature Team

Protect From Light

Access to sunlight is crucial to living systems because it’s the primary energy source for life. However, too much sunlight in the form of ultraviolet radiation (UV) can cause damage to living tissues. Therefore, living systems have strategies to filter out some or all UV radiation. For example, some plants that live in areas exposed to long periods of direct sunlight have reflective surfaces (such as white hairs or powder) that reflect UV light.

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Protists

Kingdom Protista (“the very first”): slime molds, giant kelp, red and brown algae

Protists are a numerous, diverse group of organisms that, in the simplest definition, are defined by what they are not. Protists are not plants, animals, fungi, or bacteria. Some protists, like Plasmodium, are harmful parasites that cause malaria. While many are small, obscure, and go unnoticed, others are important foodstuffs. The largest protist in the world, giant kelp (Macrocystis pyrifera), is utilized by humans and marine species for food and shelter.

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The cell coat of the amoeba provides an impermeable layer of protection via a series of tightly packed helical proteins protruding from the cell membrane.

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, 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.