Question

In which of the following functions, white muscles are not required or used?

• A. Moving of eyeballs
• B. Fast and strenuous work for short duration.
• C. Fast flight as in sparrows
• D. For sustained work at a slow rate for a long duration

Answer 1

The correct option is D

For sustained work at a slow rate for a long duration

Red muscles are for endurance, and they depend on aerobic metabolism for energy (oxidative phosphorylation). Mitochondria and Myoglobin are abundant in red muscles and there is no accumulation of lactic acid.

White muscles depend on anaerobic metabolism for energy(glycolysis). Lactic acid accumulation occurs due to glycolysis. Mitochondria are less abundant, and they perform fast and strenuous work for a short period (fast work but soon fatigue sets in).