A Level Biology Practice Exam

What role does myoglobin play in muscle tissues?

1. Transport of glucose to muscle cells

2. Storage of oxygen for muscle metabolism

3. Regulation of blood pH levels

4. Production of lactic acid during anaerobic respiration

The correct answer is: Storage of oxygen for muscle metabolism

Myoglobin plays a crucial role in muscle tissues primarily through the storage of oxygen, which is vital for aerobic metabolism. Unlike hemoglobin, which transports oxygen in the blood, myoglobin is found within muscle cells and serves to store oxygen for use during periods of intense muscular activity. When muscles are working hard and require a rapid supply of oxygen, myoglobin releases its stored oxygen to support cellular respiration. The significance of this function is particularly evident during activities that demand quick bursts of energy. Myoglobin can provide an immediate supply of oxygen, allowing muscles to maintain aerobic respiration for as long as possible before switching to anaerobic processes, which are less efficient and produce lactic acid. The other options do not accurately describe myoglobin’s function; it does not transport glucose, regulate blood pH, or produce lactic acid. Instead, these roles are managed by different molecules and systems within the body. Thus, the primary role of myoglobin in muscle tissues is indeed the storage of oxygen, making it essential for optimal muscle performance during physical activity.