Gas Exchange Lab Report

All living organisms carry out respiration, which is the production of energy - typically the intake of oxygen and the release of carbon dioxide. This process can be either aerobic or anaerobic. Cells need the energy that is formed during this process to support life processes in order for organisms to survive. Gas exchange is the process by which oxygen is taken from the air and into the bloodstream, all while carbon dioxide is released. This is where the diffusion of important gases (CO2 and O2) into and out of cells occurs, which is essential for respiration to occur. Gases are constantly required for the reactions happening in the cells, and an efficient exchange system is crucial for this to all take place. This system has been adapted

Fish use their gills and the flow of water over the gills to take in oxygen and release carbon dioxide. The process begins with the fish opening its mouth as it breathes letting in water and essentially, oxygen. It then closes its mouth and forces the water through the gills and out through the operculum (a flap of skin protecting a fish's gills), thus releasing carbon dioxide. During the process. water flows through the gills in one direction, allowing for more efficient gas exchange. It is important to distinguish that fish have an external gas exchange system, unlike insects and mammals which are

The counter current system allows the maximum amount of oxygen to diffuse into the blood from the water available. As the blood flows in the opposite direction to the water, the blood is absorbing more oxygen. Even when the blood reaches the end of the lamella and is approximately 80% saturated with oxygen, it is flowing past water, which is at the beginning of the lamella and is at least 90% saturated. Therefore, even when the blood is highly saturated, having flowed through the length of the lamellae, there is still a concentration gradient and it can continue to absorb oxygen from the water. This counter-current system is important because dissolved gases diffuse faster between fluids with a larger concentration gradient, also there isn't much oxygen in the water, and fish need to absorb enough oxygen to