Question

A student was given sample of two muscles marked as 1 and 2. When he compared the muscles he found that muscle 1 contains large amount of myoglobin and utilize large amount of stored oxygen for ATP production whereas muscle 2 contains few myoglobin, mitochondria and high sarcoplasmic reticulum. Identify the correct conclusion regarding the muscle 1 and 2 from the option given below.

• A. Both the muscles are aerobic muscles
• B. Both the muscles are called red fibres and depend on aerobic process for energy
• C. Muscle 1 is called red fibres and are aerobic muscles whereas muscle 2 is called white fibres and depend on anaerobic process for energy
• D. Muscle 1 is called white fibres and whereas muscle 2 depends on aerobic process for energy

Answer 1

The correct option is C Muscle 1 is called red fibres and are aerobic muscles whereas muscle 2 is called white fibres and depend on anaerobic process for energy

Red muscle fibre is dense with capillaries and is rich in mitochondria and myoglobin, giving the muscle tissue its characteristic red color. It can carry more oxygen and sustain aerobic activity using fats or carbohydrates as fuel.

White muscle fibre contract quickly and powerfully but fatigue very rapidly, sustaining only short, anaerobic bursts of activity before muscle contraction becomes painful. They contribute most to muscle strength and have greater potential for increase in mass. Type II is anaerobic, glycolytic, "white" muscle that is least dense in mitochondria and myoglobin.