Which is correct statement for white muscle fibre

Options

A. It contains low amount of haemoglobin and mitochondria
B. It contains higher amount of myoglobin
C. It contains low amount of myoglobin and mitochondria
D. It possesses only actin type of protein.

Answer

**Step-by-Step Text Solution:**

1. **Understanding White Muscle Fibers:**
- White muscle fibers are known for their specific characteristics that differentiate them from red muscle fibers.

2. **Composition of White Muscle Fibers:**
- White muscle fibers contain a low amount of myoglobin. Myoglobin is a protein that binds oxygen in muscle cells, and its low levels in white muscle fibers indicate a reduced capacity for oxygen storage.
- They also have a low number of mitochondria, which are the powerhouses of the cell responsible for aerobic respiration. This suggests that white muscle fibers rely less on aerobic metabolism.

3. **Presence of Smooth Endoplasmic Reticulum:**
- White muscle fibers have a higher amount of smooth endoplasmic reticulum, specifically referred to as the sarcoplasmic reticulum in muscle cells. This structure is crucial for calcium storage and release during muscle contraction.

4. **Energy Source:**
- White muscle fibers primarily depend on anaerobic processes for energy production. This means they can generate energy without the need for oxygen, making them suitable for short bursts of high-intensity activities.

5. **Comparison with Red Muscle Fibers:**
- In contrast, red muscle fibers have a high amount of myoglobin and mitochondria, which allows them to perform aerobic respiration efficiently. They are better suited for endurance activities, such as long-distance running.

6. **Conclusion:**
- The correct statement regarding white muscle fibers is that they contain low amounts of myoglobin and mitochondria, and they rely on anaerobic metabolism for energy.