When a skeletal muscle relaxes,myosin head attach to actin by breaking down ATP to ADP and phosphate with the help of myosin ATPase. The myosin head forms the cross -bridges on the active site of the actin.The cross-bridge pulls the actin which slide over the myosin. The release of ADP completes the cross-bridge movements . ATP attaches to myosin, and break the actin -myosin cross-bridge. Thus breaking of ATP into ADP and phosphate help the thin filament to return to their original position.
Answer:
What can be noticed about the ligands and their receptor is that the configuration of both coincide, as a key would with its lock, which demonstrates the specificity of a receptor by its ligand.
Explanation:
A <u>ligand</u> corresponds to a molecule considered a signal or a messenger, while the <u>receptor</u> is a protein on the cell surface, with the capacity to accept a ligand.
Ligands and receptors constitute pairs that complement each other, so that <u>each receptor can bind to a specific ligand</u>, similar to what happens with a key and a lock.
Once the ligand-receptor complex is formed, changes occur inside the cell, which define a certain effect.
It’s phenotype is brown fur.