"Under the flashes of his fellow journalists, the naked body and white Pr Adjemian sitting in his bathtub seemed like a wax figure of marinating in plum juice. Rigor mortis had done his work. The scientist was there, staring, wide open, mouth agape, eyebrows raised.
But there was something curious in body position. The left hand rested in the stagnant water of the last bath, but the right hand, she was entrenched on the edge of ceramic, index tense towards the mirror.
As if, just before his death, the scientist wanted to nominate someone or something reflecting it ... "
"Rigor mortis! "
That sounds like a dark spell walked straight out of Harry Potter ... It is not so, since we are talking about rigor mortis often mentioned in our favorite thrillers but never explained. This phenomenon, which means the hardening characteristic of the muscles begin 3 hours after death, is maximal after 12 hours and decreased gradually during the following 48 hours, and this observation may provide a rough estimate of the time of death ...
[Contents of a muscle cell observed under the microscope E - x25 000. the striated appearance is due to the presence of filaments of actin and myosin.] We have seen in the previous article (it is better to read), the muscle cell is composed of filaments: actin and myosin, which slide against each other thereby shortening the muscle, ie contraction. During this sliding settle temporarily bonds between actin and myosin. That's when the energy molecule ATP is hydrolyzed and ADP released thus far extended to the heads of the myosin molecule to retract [ see diagram].
[1] 
[2] myosin (yellow) therefore has two configurations:
[1] - The configuration high energy, or the head of the myosin molecule (yellow) is energized, like the arm of the catapult armed.
[2] - low energy configuration or the myosin head is bent and bound to actin (pink).
What happens there after death?
After death the calcium concentration increases in muscle cells, in effect charging systems to store calcium in the cell stop working tanks, and tanks they leave more and more calcium ions escape ... This increase in calcium concentration is the signal that triggers the connection between the filaments of actin and myosin.
Therefore, for the muscle returns to its relaxed state, the molecules must myosin is detached from actin filaments, and this action is only possible if a new ATP molecule is attached to the myosin to the switchover to high-energy power-up.
But after the death of ATP production is impossible and the actin and myosin are then bound irreversibly, causing rigor mortis observed. It does not disappear when the muscle proteins begin to degrade within hours after death.
to read on this subject: Wikipedia article
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