Cell locomotion

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Transcript of Cell locomotion

  • 1.Gunjan Mehta,Lecturer,Dept. Biotechnology,VSC, Rajkot

2. Movement of an entire cell in relation toits surroundings. Involves pseudopodium and ATP. Mechanism formation of new cell membrane & exocytosisat one end Attachment of pseudopodium to tissues Receptor proteins Absorption of the membrane & endocytosis inmid & rear portions Detachment of receptor proteins 3. Cells that exhibit amoeboid motion WBC Fibroblasts Embryonic cells Amoeba Control of amoeboid motion Chemotaxis Positive Negative 4. Migration of embryonic cells during development Invasion of tissues by white blood cell to fight infection The migration of cells involved in wound healing Spread of cancer cells during the metastasis of malignant tumors 5. Cilia and Flagella anatomy 6. Cilia and Flagella anatomy!This is the 9 + 2 pattern characteristic of nearly all flagella andcilia. 7. Cilia move in waves: metachronal waves. Undulatory movementPower strokeor oar likeactionFlagellar movement 8. Whiplike movement of cilia on the surfacesof cells A sharp pointed hair projecting 2-4micrometers from the surface of the cell. 9. Coveredby an outcropping of cellmembrane Supported by 11 microtubules, 9 doubletubules at the periphery and 2 singletubules down the center. Each cilium is an outgrowth of a structurethat lies immediately beneath the cellmembrane, called basal body of the cilium 10. Allthe tubules are linked to one another bya complex of protein cross linkages,together called the axoneme. Multiple protein arms composed of theprotein dynein (having ATPase activity)project outward from each double tubule ATP and appropriate magnesium andcalcium concentration required. 11. Sudden fast forward whip like stroke Slow backward stroke An effective way of pushing the fluid in thedirection of forward stroke. 12. Direction of swimming(a) Motion of flagella 5 mDirection of organisms movementPower stroke Recovery stroke(b) Motion of cilia 15 m 13. How dynein walking moves flagella and cilia: Dynein arms alternately grab, move, and release the outer microtubules Protein cross-links limit sliding Forces exerted by dynein arms cause doublets to curve, bending the cilium or flagellum 14. Fig. 6-25Microtubuledoublets ATPDyneinprotein(a) Effect of unrestrained dynein movement ATPCross-linking proteinsinside outer doubletsAnchoragein cell(b) Effect of cross-linking proteins1 32(c) Wavelike motion 15. Fig. 6-25a Microtubule doublets ATP Dynein protein (a) Effect of unrestrained dynein movement 16. Fig. 6-25bATP Cross-linking proteins inside outer doublets Anchorage in cell (b) Effect of cross-linking proteins 13 2 (c) Wavelike motion 17. CELLSEXHIBITING CILIARY MOVEMENT 1- Respiratory airways 2- Uterine tubes of the female reproductivetract. 18. Q&A