This is a free preview. For full access
Musculoskeletal System
Calcium Control in Muscle Contraction
Description
Calcium control in muscle contraction depends on ATP, motor neurons, and the sliding action of actin and myosin. As a muscle contracts, the thin and thick filaments overlap more, and the sarcomere, which is the contractile unit of the muscle, becomes shorter. This process uses energy from ATP and happens in a repeating cycle...
Show More
Transcript
当细丝和粗丝的
重叠增加时 肌肉收缩
导致肌节长度减小
在分子水平上 当与肌球蛋白的
球状头部区域结合的ATP水解成ADP时
发生收缩 将肌球蛋白头转化为高能状态
其中它与肌动蛋白结合
并产生交叉桥
ADP的释放导致肌球蛋白头部
恢复到低能量状态
使肌动蛋白朝向肌节中心移动
新的ATP分子与肌球蛋白头的结合
然后将其与肌动蛋白解离
下一次这个肌球蛋白头部
与肌动蛋白结合时
它将位于更接近Z线...
Show More