Final answer:
Gas exchange at the alveolar capillary junction occurs through diffusion. This process involves the movement of oxygen and carbon dioxide molecules across cell membranes, from an area of higher concentration to an area of lower concentration.
Step-by-step explanation:
Gas exchange at the alveolar capillary junction occurs through diffusion. This process involves the movement of oxygen and carbon dioxide molecules across cell membranes, from an area of higher concentration to an area of lower concentration.
Diffusion is a passive process that does not require energy. It takes place due to the large surface area provided by the alveoli in the lungs and the concentration gradient maintained by continuous blood flow and breathing.