Final answer:
The physiological response to lactate buildup in the blood is acidosis, which is characterized by decreased blood pH. Lactate is produced from pyruvic acid during intense exercise and is eventually metabolized in the liver.
Step-by-step explanation:
When lactate builds up in the blood as a result of intense exercise, a physiological response known as acidosis occurs. Lactate production happens during anaerobic glycolysis, where pyruvic acid is converted to lactic acid in the presence of the enzyme lactate dehydrogenase (LDH). This buildup can lead to a decreased pH of the blood, as the lactic acid dissociates into lactate and hydrogen ions (H+), thereby increasing the acidity of the blood. If not managed, this can contribute to muscle fatigue and discomfort. However, lactic acid can be transported out of the muscles and into the liver, where it is converted back to pyruvic acid and further utilized for energy production, mitigating the acidic conditions over time.