(eli5) How do muscles contract on a molecular level?

Question

(eli5) How do muscles contract on a molecular level?

In: Chemistry

Answer 1

There are two main proteins in muscle called myosin and actin. Myosin has little clublike parts that attach to the long skinny actin. In response to a tiny change in cell chemistry the myosin clubs bind and release onto the actin so the myosin “walks” along the actin and the whole myosin / actin unit gets shorter and fatter. Multiply this by many thousands of units and the whole muscle fibre gets shorter and fatter. Multiply that by the number of fibres in action and the whole muscle gets shorter and fatter.