Structure
Amoeboids move using pseudopodia, which are bulges of cytoplasm.
Amoebas breathe using their entire cell membrane that is constantly immersed in water. Excess water can cross into the cytosol. Amoebas have a contractile vacuole to expel excess water.
Food sources vary in amoeboids. They may consume bacteria or other protists. Some are detritivores and eat dead organic material. They extend a pair of pseudopodia around food. They fuse to make a food vacuole which then fuses with a lysosome to add digestive chemicals. Undigested food is expelled at the cell membrane.
Amoebas use pseudopodia to move and feed. They are powered by flexibe microfilaments near the membrane. Microfilaments are at least 50% of the cytoskeleton. The other parts are more stiff and are composed of intermediate filaments and microtubules. These are not used in amoeboid movement, but are stiff skeletons on which organelles are supported or can move on.
The shells of amoebas are often composed of calcium. The proteins or materials are synthesised in the cell and exported just outside the cell membrane.
Read more about this topic: Amoeboid
Famous quotes containing the word structure:
“The philosopher believes that the value of his philosophy lies in its totality, in its structure: posterity discovers it in the stones with which he built and with which other structures are subsequently built that are frequently better—and so, in the fact that that structure can be demolished and yet still possess value as material.”
—Friedrich Nietzsche (1844–1900)
“Why does philosophy use concepts and why does faith use symbols if both try to express the same ultimate? The answer, of course, is that the relation to the ultimate is not the same in each case. The philosophical relation is in principle a detached description of the basic structure in which the ultimate manifests itself. The relation of faith is in principle an involved expression of concern about the meaning of the ultimate for the faithful.”
—Paul Tillich (1886–1965)
“The structure was designed by an old sea captain who believed that the world would end in a flood. He built a home in the traditional shape of the Ark, inverted, with the roof forming the hull of the proposed vessel. The builder expected that the deluge would cause the house to topple and then reverse itself, floating away on its roof until it should land on some new Ararat.”
—For the State of New Jersey, U.S. public relief program (1935-1943)