Question

Without ATP, the myosin heads cannot detach from the actin-binding sites. All of the "stuck" cross-bridges result in muscle stiffness. In a live person, this can cause a condition like "writer's cramps." In a recently dead person, it results in rigor mortis.

a) True
b) False

Answer 1

Without ATP, myosin heads cannot release from actin, causing muscle stiffness; alive, this can lead to 'writer's cramps,' while in the deceased, it results in rigor mortis.

Step-by-step explanation:

It is true that without ATP, the myosin heads cannot detach from the actin-binding sites, causing muscle stiffness. In a living person, this condition can cause 'writer's cramps' and in a recently deceased individual, this results in rigor mortis. During muscle contraction, myosin heads form cross-bridges with actin, which are released when another ATP molecule binds to myosin, allowing muscles to relax. After death, when ATP synthesis ceases, these cross-bridges cannot detach, resulting in the stiffness characteristic of rigor mortis.