How do our muscles contract? Think about it!
Our muscles visibly contract and relax, but these movements occur on a microscopic scale!
Just as a single team-mate is the most basic unit of a sports team, a sarcomere (sahr-co-meer) is the most basic functional unit of a muscle cell.
There are thousands of sarcomeres in one muscle cell! These sarcomeres give muscle its striated appearance.
But, how does this explain how muscles work?
Let's take a closer look...
A sarcomere (there muscle) is composed of these two proteins.
Actin and myosin must interact, but first they need some help...
Actin and myosin need calcium (Ca2+) and energy (ATP) to be attracted to each other!
The actin and myosin proteins slide along each other, causing muscles ([containing] sarcomeres) to contract.
Well, this has been an "exercise" in thinking!