cytoplasmic streaming

cytoplasmic streaming

also called  protoplasmic streaming 
 the movement of the fluid substance (cytoplasm) within a plant or animal cell. The motion transports nutrients, proteins, and organelles within cells. 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 mediated by “motor” proteins—molecules made up of two proteins that use adenosine triphosphate (ATP) to move one protein in relation to the other. If one of the proteins remains fixed on a substrate, such as a microfilament or a microtubule, the motor proteins can move organelles and other molecules through the cytoplasm. Motor proteins often consist of actin filaments, long protein fibres aligned in rows parallel to the streaming just inside the cell membrane. Myosin molecules attached to cellular organelles move along the actin fibres, towing the organelles and sweeping other cytoplasmic contents in the same direction.

* * *


Universalium. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Cytoplasmic streaming — is the directed flow of cytosol (the liquid component of the cytoplasm) and organelles around large fungal and plant cells. This movement aids in the delivery of nutrients, metabolites, genetic information, and other materials to all parts of the …   Wikipedia

  • cytoplasmic streaming — protoplasmic streaming cyclosis …   Medical dictionary

  • cytoplasmic streaming — Bulk flow of the cytoplasm of cells. Most conspicuous in large cells such as amoebae and the internodal cells of Chara where the rate of movement may be as high as 100 m m/sec. See cyclosis …   Dictionary of molecular biology

  • cell — cell1 cell like, adj. /sel/, n. 1. a small room, as in a convent or prison. 2. any of various small compartments or bounded areas forming part of a whole. 3. a small group acting as a unit within a larger organization: a local cell of the… …   Universalium

  • Charales — Stoneworts Chara globularis Scientific classification Kingdom: Plantae …   Wikipedia

  • circulation — circulable /serr kyeuh leuh beuhl/, adj. /serr kyeuh lay sheuhn/, n. 1. an act or instance of circulating, moving in a circle or circuit, or flowing. 2. the continuous movement of blood through the heart and blood vessels, which is maintained… …   Universalium

  • fungus — fungic /fun jik/, adj. funguslike, adj. /fung geuhs/, n., pl. fungi /fun juy, fung guy/, funguses, adj. n. 1. any of a diverse group of eukaryotic single celled or multinucleate organisms that live by decomposing and absorbing the organic… …   Universalium

  • Motion (physics) — Motion involves change in position, such as in this perspective of rapidly leaving Yongsan Station In physics, motion is a change in position of an object with respect to time. Change in action is the result of an unbalanced force. Motion is… …   Wikipedia

  • Slime mold — Not to be confused with slime bacteria. Slime mold Stemonitis fusca in Scotland, UK …   Wikipedia

  • angiosperm — /an jee euh sperrm /, n. Bot. a plant having its seeds enclosed in an ovary; a flowering plant. Cf. gymnosperm. [ANGIO + SPERM] * * * ▪ plant Introduction       any member of the more than 300,000 species of flowering plants (division Anthophyta) …   Universalium

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”