Tag: gas exchange and smoking

• Respiration is the movement of oxygen from the outside environment to the cells within tissues and the transport of carbon dioxide in the opposite direction.
•  During cellular respiration, glucose is broken down in the presence of oxygen to produce carbon dioxide and water. 
• The energy released during the reaction is captured by the energy-carrying molecule ATP (adenosine triphosphate). Hence, The energy releasing process in living organisms is respiration.

Physiological respiration is the complete process of respiration which includes physical and biochemical pathway. In physical pathway, there is an exchange of gasses that takes place with the help of respiratory organ i.e., lungs. In biochemical pathway, cells are involved where oxidation of food i.e. glucose takes place in mitochondria and cytoplasm in the presence of several respiratory enzymes. 

Fish brought out of water die due to inability to respire. Fish gills are specialized for extracting oxygen from water and cannot effectively extract oxygen from air. The gills collapse and dry out outside water, making gas exchange impossible.