Answer:
Sarcomere
Explanation:
A sarcomere is the basic contractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments—actin and myosin—which are the active structures responsible for muscular contraction.
Chemical energy into kinetic energy
Answer:
b. to amplify the signal
Explanation:
A multi-enzyme phosphorylation cascade is a series of signaling events where one enzyme phosphorylates to another, then this last enzyme acts to phosphorylate another protein and so successively, thereby triggering a chain reaction that leads to the phosphorylation of hundreds or even thousands of proteins. A multi-enzyme phosphorylation cascade is known to increase the number of activated (phosphorylated) proteins at each step of the signaling cascade. Phosphorylation is a posttranslational modification capable of activating proteins during long periods, thereby a phosphorylation cascade also enables the activation of multiple proteins before these proteins become inactive again.
