Actomyosin filaments and ATP - heart of rigor mortis
It is a well-known fact that contractile substance of the muscle fibril is actomyosin, a complex composed of two protein filaments- actin (thin filament) and myosin (Thick filament), which require adenosine triphosphate (ATP), as a source of energy for their sliding movement. So after death due to non-availability of ATP, the thick and thin filaments can't slide away from each other and the muscles stay in a contracted state, known as rigor mortis (stiffness of body). Although this helps explain how the rigor mortis comes and goes, it also help us to explore how the gradual progression of rigor mortis plays a part in solving crimes by estimating the time since death.
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