Most lactic acid is removed …
a. by breaking back down to pyruvic acid and recycle for heart and skeletal tissue energy later
b. by breaking down into muscle fat
c. by breaking down into urine
d. by breaking down into water for sweat
The correct answer and explanation is:
The correct answer is a. by breaking back down to pyruvic acid and recycle for heart and skeletal tissue energy later.
Lactic acid is a byproduct of anaerobic metabolism, which occurs when the body needs energy quickly and oxygen supply to the muscles is insufficient. This typically happens during intense physical activity. When muscles undergo anaerobic glycolysis, glucose is converted into pyruvic acid. However, due to the lack of oxygen, pyruvic acid is then converted into lactic acid.
The body needs to remove this lactic acid to prevent a buildup, which could cause fatigue and soreness. The majority of lactic acid is transported from the muscles to the liver, where it undergoes a process called the Cori cycle. During the Cori cycle, lactic acid is converted back into pyruvic acid. Pyruvic acid can then be used for energy production or converted into glucose through a process called gluconeogenesis. This glucose can later be used by muscles, heart tissue, or other organs for energy.
In this way, lactic acid is not just a waste product, but also a resource that the body recycles. The heart and skeletal muscles can use this recycled pyruvic acid for energy production when oxygen levels are restored and energy demands are high. This recycling process is important for efficient energy management during and after intense physical exertion.
Other options like breaking lactic acid into muscle fat or urine are not the primary ways lactic acid is removed. While some waste products are excreted in urine, lactic acid is mostly processed through the Cori cycle and is used as a source of energy later. Similarly, sweating involves the removal of water and electrolytes, not lactic acid.