Slow Twitch Fibers Appear Red Due to the Intracellular Storage

Question

Slow twitch fibers appear red due to the intracellular storage of ________.
A) nebulin
B) titin
C) hemoglobin
D) glycogen
E) myoglobin

Accepted Answer

Slow twitch fibers are also called type I fibers and they have a high concentration of myoglobin, an oxygen-binding protein in muscle tissue. Myoglobin is responsible for the reddish color of slow twitch fibers. Choices A, B, D are not related to the color of muscle fibers, while hemoglobin is found in red blood cells, not inside muscle fibers.