Question

Anaerobic breakdown of glucose in our muscles produces.

• A. Pyruvic acid
• B. Lactic acid
• C. Ethyl alcohol
• D. Oxalic acid

Answer 1

The correct option is B Lactic acid

Glycolysis is the transformation of glucose to pyruvate when limited amounts of oxygen are available. Glycolysis is only an effective means of energy production during short, intense exercise, providing energy for a period ranging from 10 seconds to 2 minutes. During the processes of glycolysis, hydrogen ions (H+) are released into the muscle cell. Without oxygen the H+ cannot be removed and as a result the muscle cell becomes increasingly acidic. During high intensity exercise the products of anaerobic glycolysis namely pyruvate and H+ accumulate rapidly. Lactate is formed when one molecule of pyruvate attaches to two H+ ions. The lactate is then quickly removed from the muscle cell, protecting the cell from becoming too acidic so exercise can continue for a little longer. However as intense exercise continues, we reach a point where we cannot remove enough lactate from our muscles to control the acidosis caused by the rapid accumulation of H+. When this happens we are unable to sustain the intensity of exercise and have to either cease exercise or reduce the intensity.