Breakdown of pyruvate into lactic acid and energy in lack of oxygen takes place in which of the following?

Human muscle cells

The correct answer is Option (2) – Human muscle cells

The breakdown of pyruvate into lactic acid and energy in the absence of oxygen is a process known as anaerobic respiration, specifically lactic acid fermentation. This process occurs in various organisms, including human muscle cells.

When oxygen levels are low, such as during intense physical activity when oxygen demand exceeds supply, muscle cells switch from aerobic respiration (which occurs in the mitochondria) to anaerobic respiration. In anaerobic conditions, pyruvate produced from glycolysis is converted into lactic acid.

In human muscle cells, lactic acid fermentation allows for the rapid production of ATP (energy) to sustain muscle contraction when oxygen supply is limited. The accumulation of lactic acid in muscle cells contributes to muscle fatigue and soreness experienced during strenuous exercise.

While bacteria and yeast also undergo fermentation processes, the breakdown of pyruvate into lactic acid specifically in the context of muscle cells is essential for energy production during anaerobic conditions in humans.