Question

What are the contractile proteins that slide across each other allowing the muscle fiber to shorten?
GPT 3.5
The contractile proteins that slide across each other allowing the muscle fiber to shorten are actin and myosin. These two proteins are responsible for the contraction of muscles through a process known as the sliding filament theory. When a muscle is stimulated to contract, myosin heads attach to binding sites on actin filaments and pull them towards the center of the sarcomere, causing the muscle fiber to shorten and generate force.