What are the two regulatory proteins found in skeletal muscle?

The two regulatory proteins found in skeletal muscle are tropomyosin and troponin. These proteins play a critical role in the regulation of muscle contraction.

Troponin is a complex of three proteins that binds to calcium ions released during muscle activation. When calcium is present, troponin undergoes a conformational change that causes tropomyosin to move away from the binding sites on actin filaments, allowing myosin heads to attach to actin and initiate contraction.

Tropomyosin, on the other hand, is a long, filamentous protein that lies alongside actin filaments. Its primary function is to stabilize the actin structure and regulate access to the binding sites, which is crucial during the muscular contraction process.

In summary, these regulatory proteins work together to control the interaction between actin and myosin, thus modulating muscle contraction based on the availability of calcium ions.