- ?Lv 62 0 年前最佳解答
Cytoplasmic streaming, or the flowing of cytoplasm in eukaryotic cells, aids in the delivery of nutrients, metabolites, and genetic information to all parts of larger plant cells. It vigorously "stirs" these components about the cytoplasm. As membrane-bound organelles crawl along the inner cell wall they set the cytoplasm into motion. This streaming allows other organelles and nutrients to flow in the stream created. This allows the components of the cell to flow around the cell and balance the amount of nutrients that exist in different parts of the cell providing nutrients and enzymes, as well as a means of motion for unicellular eukaryotes, like amoeba.
also called protoplasmic streaming the movement of the living substance (cytoplasm) within a plant or animal cell. The motion transports nutrients, enzymes, and, in plants, large virus particles within cells. In unicellular organisms such as amoeba, it provides the mechanism for cell locomotion. First discovered in the 1830s, the presence of cytoplasmic streaming helped convince biologists that cells were the fundamental units of life.
Although the mechanism of cytoplasmic streaming is not completely understood, it is thought to be driven by actin filaments, long protein fibres aligned in rows parallel to the streaming just inside the cell membrane. Myosin molecules attached to cellular organelles may move along the actin fibres, towing the organelles and sweeping other cytoplasmic contents in the same direction.
And here's a really good review in cytoplasmid streaming in plants:
Shimmen T, Yokota F, Curr Opin Cell Biol. 2004 Feb;16(1):68-72.參考資料： http://en.wikipedia.org/wiki/Cytoplasmic_streaming AND http://www.britannica.com/eb/article-9028448