Agree
it is no active to use energy to move or be in motion
The answer is sliding filament.
Muscle fibers are made up of myosin and actin filaments that straddle one another in alternating sequence. The myosin has myosin heads that act on the actin and enable the myofibrils to slide across each other in opposite directions. This causes the muscle to shorten hence contract. This is an energy-requiring process (hence hydrolyses ATP) and also requires calcium ions. In an animation, the myosin would seem to ‘walk’ on the actin filament.
A biochemist studies the living beings, the chemical processes that go on in their bodies and the different ways in which they get energy from food.
