Where does anaerobic glycolysis occur within the muscle cell?

Where does anaerobic glycolysis occur within the muscle cell?

• A. Cytosol of muscle cell
• B. Mitochondrial matrix
• C. Sarcoplasm of muscle cell
• D. Nucleus

Answer: (C)

Glycolysis runs in the cell’s cytosol, and in muscle fibers that cytosolic space is called the sarcoplasm. That’s where the glycolytic enzymes are located and where glucose is split into pyruvate, yielding a small amount of ATP. Under anaerobic conditions, the pyruvate is reduced to lactate to regenerate NAD+, allowing glycolysis to continue without oxygen. The mitochondrial matrix is where aerobic respiration happens, so it’s not the site for anaerobic glycolysis. The nucleus isn’t involved in the glycolytic steps. So the sarcoplasm—the muscle cell’s cytoplasm—is the correct location.

Glycolysis runs in the cell’s cytosol, and in muscle fibers that cytosolic space is called the sarcoplasm. That’s where the glycolytic enzymes are located and where glucose is split into pyruvate, yielding a small amount of ATP. Under anaerobic conditions, the pyruvate is reduced to lactate to regenerate NAD+, allowing glycolysis to continue without oxygen. The mitochondrial matrix is where aerobic respiration happens, so it’s not the site for anaerobic glycolysis. The nucleus isn’t involved in the glycolytic steps. So the sarcoplasm—the muscle cell’s cytoplasm—is the correct location.