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microfilament

microfilament Any of numerous microscopic protein fibres, typically 7–9 nm in diameter, that form one of the main components of the cytoskeleton of eukaryotic cells. Each microfilament consists of two helically twisted strands, each comprising a chain of globular subunits of the protein actin. They can shorten or extend by the removal or addition of subunits and are linked by cross-linking proteins to form three-dimensional networks. Bundles of microfilaments often occur just beneath the cell surface, typically oriented parallel to the long axis of the cell, and some are anchored to the plasma membrane. With the aid of the motor protein myosin the microfilaments can slide relative to each other, causing contractile movements, as in muscle cells, or other changes in cell shape, such as those occurring in amoeboid movement. They are also involved in the transport of materials within the cell, and in the peripheral flow of cytoplasm and cell organelles known as cytoplasmic streaming. Hence microfilaments play a crucial role in the growth of cell extensions, for example the pollen tube that develops from a germinating pollen grain. Compare microtubule. See also intermediate filament.

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"microfilament." A Dictionary of Biology. . Encyclopedia.com. 21 Jul. 2017 <http://www.encyclopedia.com>.

"microfilament." A Dictionary of Biology. . Encyclopedia.com. (July 21, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/microfilament-1

"microfilament." A Dictionary of Biology. . Retrieved July 21, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/microfilament-1

microfilament

microfilament A filament. 0.4–0.7 nm in diameter, that is composed of the protein actin. Microfilaments often occur in abundance immediately beneath the plasma membrane, and play a role in cell motility, cytokinesis, and cytoplasmic streaming.

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"microfilament." A Dictionary of Plant Sciences. . Encyclopedia.com. 21 Jul. 2017 <http://www.encyclopedia.com>.

"microfilament." A Dictionary of Plant Sciences. . Encyclopedia.com. (July 21, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/microfilament

"microfilament." A Dictionary of Plant Sciences. . Retrieved July 21, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/microfilament

microfilament

microfilament A filament, 0.4–0.7 nm in diameter, containing the protein actin. Such structures often occur in abundance immediately beneath the cell membrane and play a role in cell motility and cytokinesis (see MITOSIS).

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"microfilament." A Dictionary of Zoology. . Encyclopedia.com. 21 Jul. 2017 <http://www.encyclopedia.com>.

"microfilament." A Dictionary of Zoology. . Encyclopedia.com. (July 21, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/microfilament-0

"microfilament." A Dictionary of Zoology. . Retrieved July 21, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/microfilament-0