Motilitas

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Pembelahan sel. Semua sel dapat dianggap motil karena dapat membelah menjadi dua sel anakan.[1]
Sitoskeleton eukariotik menginduksi sel untuk bergerak melalui permukaan cair dan lebih, membelah menjadi sel-sel baru, dan sitoskeleton membimbing pengangkutan organel dalam sel. Video ini menunjukkan sitoskeleton yang diwarnai dari potongan melintang daun Arabidopsis thaliana.[2]

Motilitas adalah kemampuan suatu organisme untuk bergerak secara independen, menggunakan energi metabolik.[3][4] Ini berbeda dengan mobilitas, yang menggambarkan kemampuan suatu objek untuk dipindahkan. Motilitas ditentukan secara genetik,[5] tetapi mungkin dipengaruhi oleh faktor lingkungan. Sebagai contoh, otot memberikan hewan motilitas tetapi konsumsi hidrogen sianida (faktor lingkungan dalam kasus ini) akan mempengaruhi fisiologi otot yang menyebabkan otot tersebut kaku yang mengarah ke rigor mortis.[6][7][8] Selain lokomosi hewan, kebanyakan hewan adalah motil (beberapa bergerak dengan lokomosi pasif) – istilah ini berlaku untuk bakteri dan mikroorganisme lainnya, dan untuk beberapa organisme multiseluler, serta beberapa mekanisme aliran cairan di organ dan jaringan multiseluler. Hewan laut yang motil umumnya disebut sebagai hewan yang berenang bebas,[9][10][11] dan organisme non-parasit yang motil disebut sebagai hewan yang hidup bebas.

Motilitas juga mengacu pada kemampuan organisme untuk memindahkan makanan melalui saluran pencernaannya. Ada dua jenis motilitas usus – peristalsis dan segmentasi.[12] Motilitas ini disebabkan oleh kontraksi otot-otot polos di saluran pencernaan yang mencampur isi luminal dengan berbagai sekresi (segmentasi) dan memindahkan isi melalui saluran pencernaan dari mulut ke anus (peristaltik).[13]

Lihat pula[sunting | sunting sumber]

Referensi[sunting | sunting sumber]

  1. ^ Clegg, Chris (2008). "3.2 Cells make organisms". Edexcel biology for AS (edisi ke-6th). London: Hodder Murray. hlm. 111. ISBN 978-0-340-96623-5. Division of the cytoplasm, known as cytokinesis, follows telophase. During division, cell organelles such as mitochondria and chloroplasts become distributed evenly between the cells. In animal cells, division is by in-tucking of the plasma membrane at the equator of the spindle, 'pinching' the cytoplasm in half (Figure 3.15). In plant cells, the Golgi apparatus forms vesicles of new cell wall materials which collect along the line of the equator of the spindle, known as the cell plate. Here, the vesicles coalesce forming the new plasma membranes and cell walls between the two cells (Figure 3.17). 
  2. ^ Alberts, Bruce; Johnson, Alexander; Lewis, Juian; Raff, Martin; Roberts, Keith; Walter, Peter (2008). "16". Molecular biology of the cell (edisi ke-5th). New York: Garland Science. hlm. 965. ISBN 0-8153-4106-7. For cells to function properly, they must organize themselves in space and interact mechanically with their environment... Eucaryotic cells have developed... the cytoskeleton... pulls the chromosomes apart at mitosis and then splits the dividing cell into two... drives and guides intracellular traffic of organelles... enables cells such as sperm to swim and others, such as fibroblasts and white blood cells, to crawl across surfaces. 
  3. ^ "Motility" (PDF). Diakses tanggal 10 March 2018. 
  4. ^ "Online Etymology Dictionary". "capacity of movement," 1827, from French motilité (1827), from Latin mot-, stem of movere "to move" (see move (v.)). 
  5. ^ Nüsslein-Volhard, Christiane (2006). "6 Form and Form Changes". Coming to life: how genes drive development. [San Diego, CA]: Kales Press. hlm. 75. ISBN 0979845602. During development, any change in cell shape is preceded by a change in gene activity. It is the cell's origin and environment that determine which transcription factors are active within a cell, and, hence, which genes are turned on, and which proteins are produced. 
  6. ^ Fullick, Ann (2009). "7.1". Edexcel A2-level biology. Harlow: Pearson. hlm. 138. ISBN 978-1-4082-0602-7. Cyanide is well known in murder mysteries - and has been used in real murders too. The poison acts on cytochrome oxidase in the electron transport chain, preventing the production of ATP. The cells of the body cannot function without their energy supply, so the muscles spasm and the victim cannot breathe. 
  7. ^ Fullick, Ann (2009). "6.1". Edexcel A2-level biology. Harlow: Pearson. hlm. 67. ISBN 978-1-4082-0602-7. As the muscles run out of ATP, the muscle fibres become permanently contracted and lock solid. This produces a stiffening effect which is known as rigor mortis. 
  8. ^ E. Cooper, Chris; C. Brown, Guy (October 2008). "The inhibition of mitochondrial cytochrome oxidase by the gases carbon monoxide, nitric oxide, hydrogen cyanide and hydrogen sulfide: chemical mechanism and physiological significance". Journal of Bioenergetics and Biomembranes. 40 (5): 533–539. doi:10.1007/s10863-008-9166-6. 
  9. ^ Krohn, Martha M.; Boisdair, Daniel (May 1994). "Use of a Stereo-video System to Estimate the Energy Expenditure of Free-swimming Fish". Canadian Journal of Fisheries and Aquatic Sciences. 51 (5): 1119–1127. doi:10.1139/f94-111. 
  10. ^ Cooke, Steven J.; Thorstad, Eva B.; Hinch, Scott G. (March 2004). "Activity and energetics of free-swimming fish: insights from electromyogram telemetry". Fish and Fisheries. 5 (1): 21–52. doi:10.1111/j.1467-2960.2004.00136.x. We encourage the continued development and refinement of devices for monitoring the activity and energetics of free-swimming fish 
  11. ^ Carey, Francis G.; Lawson, Kenneth D. (February 1973). "Temperature regulation in free-swimming bluefin tuna". Comparative Biochemistry and Physiology A. 44 (2): 375–392. doi:10.1016/0300-9629(73)90490-8. Acoustic telemetry was used to monitor ambient water temperature and tissue temperature in free-swimming bluefin tuna (Thunnus thynnus Linneaus [sic], 1758) over periods ranging from a few hours to several days. 
  12. ^ Intestinal Motility Disorders di eMedicine
  13. ^ Wildmarier, Eric P.; Raff, Hershel; Strang, Kevin T. (2016). Vander's Human Physiology: The Mechanisms of Body Function (14th ed). New York, NY: McGraw Hill. hlm. 528.