• 커뮤니티
  • 세미나/콜로퀴움
세미나/콜로퀴움

12/8 PHYSICS Colloquium(신현정 교수)

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"                PHYSICS Colloquium


          “Force of a Biological Engine”
    

    
        ▶ 연사 : 신현정 교수 [KAIST]
        ▶ 일시 : 2006 년 12월 8일(금) 오후 3시
        ▶ 장소 : 무은재 기념관 307호 (멀티미디어 강의실)  

The conversion of chemical energy into mechanical forces that powers cell movements is a ubiquitous theme across biology.The most famous example is the dynamics of molecular motors such as kinesin-microtubule and actin-myosin complexes.Yet, not all biological movements are caused by molecular motors sliding along tubules or filaments.Biological springs and ratchets can also store and release energy to rectify motion. Recent experimental advances have led to the study of these dynamic phenomena in biology that can be rationalized using ideas from physics, mathematics, and mechanics.The acrosome reaction of horseshoe crab sperm is a simple example of a biological spring where a 60 mm-long crystalline bundle of actin filaments, tightly cross-linked by actin bundling protein scruin, straightens from a coiled conformation and extends from the cell in five seconds. To identify the basis and mechanism for this movement, we examine the possible sources of chemical and mechanical energy and show that the stored elastic energy alone is sufficient to drive the reaction.Our experiments are also the first to measure the force generated by an actin spring.  For the sperm cells, the jelly coatof the egg represents a formidable physical barrier to fertilization.  The solution to this biological problem lies in a simple engineering device - an actin spring.  We show that actin enhances its versatility as a biopolymer with the abilities to store and release elastic energy, and produce force and motion mechanically, all the while enabling asperm cell to achieve fertilization.


      문의처: 성우경 교수(054-279-2061, wsung@postech.ac.kr)
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