Question

Read the following scenario to answer the following questions. An abundant and continual supply of ATP is necessary for all living cells. Toxins, reduced blood flow, and a compromised respiratory system can interfere with the transport of oxygen to active cells. A runner in a marathon faces multiple obstacles to continue to produce sufficient ATP to remain competitive. When the circulatory system cannot deliver oxygen fast enough to support a runner's aerobic metabolism, cells switch to an emergency mode in which ________.

Answer 1

Answer:

...cells switch to an emergency mode in which the body uses anaerobic metabolism during exercise to provide the necessary fuel for the muscles.

Explanation:

Anaerobic metabolism is the generation of energy by burning carbohydrates in the absence of oxygen. This happens when the lungs cannot place enough oxygen in the bloodstream to meet the energy demands of the muscles. It is used only for short periods of activity.

When there is not enough oxygen in the bloodstream, glucose and glycogen cannot be broken down into carbon dioxide and water. Instead, lactic acid is produced, which can accumulate in the muscles and degrade muscle function.