Final answer:
Under anaerobic conditions, skeletal muscle converts pyruvate to lactate to generate ATP, ensuring continued energy provision for activities like high-intensity exercise when oxygen is limited.
Step-by-step explanation:
Under anaerobic conditions, skeletal muscle generates lactate from pyruvate primarily to generate ATP. This process, termed anaerobic glycolysis, allows for the continual production of ATP and the regeneration of NAD+ from NADH, which is essential for sustained glycolytic activity during conditions of limited oxygen supply.
When muscles engage in high-intensity exercise, they consume ATP more rapidly than it can be produced through aerobic respiration, hence they switch to anaerobic respiration to fulfill the immediate energy demands.
During anaerobic glycolysis, there is a net gain of two ATP molecules for the cell. The lactate produced can accumulate in the muscles, leading to fatigue, but is eventually transported to the liver. There, it can either be re-oxidized to pyruvate or enter the Cori cycle to be converted back into glucose. This process is critical in maintaining temporary energy needs when oxygen is scarce, such as during strenuous exercise.