Final answer:
Carbon dioxide production in the working muscle increases due to aerobic metabolism, resulting in an increase in tissue partial pressure of CO₂.
Step-by-step explanation:
Carbon dioxide (CO₂) production in the working muscle will increase as a result of aerobic metabolism resulting in a(n) increase in tissue partial pressure of CO₂. The working muscles produce more CO₂ because they have a high rate of metabolic activity, especially during periods of exercise or exertion. When muscle cells metabolize glucose via the Krebs cycle and chemiosmosis, CO₂ is a byproduct; as glycogen and fat reserves are used to fuel these pathways, CO₂ levels rise in the muscle tissue. This causes a gradient where the partial pressure of CO₂ is higher in tissues than in the blood, allowing for the diffusion of CO₂ out of the muscle and into the blood. CO₂ is then transported to the lungs bound to hemoglobin, dissolved in plasma, or as bicarbonate. In the lungs, these processes reverse, allowing CO₂ to be exhaled.