Final answer:
The mitochondria would exhibit high activity levels when lactic acid to pyruvic acid conversion increases as they are responsible for the Krebs cycle and ATP production during aerobic respiration.
Step-by-step explanation:
Which Cell Organelle is Active During Lactic Acid to Pyruvic Acid Conversion?
When the ratio of lactic acid to pyruvic acid increases, it indicates a transition from anaerobic to aerobic metabolism, suggesting that the body is recovering from a state of oxygen debt typical after exercise. The organelle that would have a heightened level of activity is the mitochondria. This is because the mitochondria are responsible for aerobic respiration where pyruvate, the oxidized form of lactic acid, enters the Krebs cycle and is further metabolized to generate energy in the form of adenosine triphosphate (ATP). The conversion of lactic acid back to pyruvic acid is crucial as it provides metabolites necessary for the continued production of energy via the mitochondria's role in oxidative phosphorylation, making the mitochondria the cell's powerhouse.
The nucleus, endoplasmic reticulum, and Golgi apparatus are involved in processes like protein synthesis and modification, which are not directly related to the lactic acid to pyruvic acid conversion. It's the mitochondria that play the central role in cellular respiration, energy production, and metabolism of pyruvic acid, thus their activity increases when levels of pyruvate rise after lactic acid has been converted back.