The relatively high maximum velocity of shortening of a skeletal muscle containing predominately type II fibers can be partially attributed to a relative abundance of which of the following substances, compared to a muscle containing predominately type I fibers?
A)Blood capillaries
B)Mitochondria
C)Myoglobin
D)Myosin adenosine triphosphatase
E)Oxidative enzymes

Question

Quizplus · Accepted Answer

Type II fibers have a higher concentration of myosin adenosine triphosphatase (ATPase) compared to type I fibers. Myosin ATPase is responsible for the hydrolysis of ATP which powers muscle contraction. Therefore, a higher concentration of myosin ATPase in type II fibers allows for a faster and more forceful contraction, contributing to a higher maximum velocity of shortening.

The Relatively High Maximum Velocity of Shortening of a Skeletal