Question

Differentiate between external respiration and internal respiration.

Answer 1

Hint:Respiration is the process where oxygen moves from the external environment to the cells within the tissues and carbon dioxide is transported in the opposite direction. During the gas exchange in animals, oxygen and carbon dioxide diffuse in and out of the blood in lungs and metabolizing tissues. The gas exchange occurs at the respiratory membrane in lungs and in metabolizing tissues like skeletal muscles. The partial pressure gradient of each gas determines the direction and the rate of diffusion across the respiratory membrane.

Complete answer:

Serial No.	Internal Respiration	External Respiration
1	The internal respiration depicts the gas as being exchanged across the respiratory membrane in the metabolizing tissues.	In external respiration, depicts the gas as being exchanged across the respiratory membrane of lungs.
2.	Internal respiration occurs in every cell. Where the oxygen is used in the mitochondria inside the cell so the energy can be released.	The external respiration is the act of breathing. When we inhale, the air containing oxygen enters the lungs. From the lung, then it is carried to the cells through the bloodstream. In the same way, the carbon dioxide is released when we exhale.
3.	The internal respiration can be found in every living organ. The plants and animals, both do the internal respiration.	The external respiration only occurred in the cases of animals. The respiration can’t be seen in plants. Through stomata, the oxygen is absorbed at the time of photosynthesis.

Note:The partial pressure of oxygen is 100 mmHg and it is 40 mmHg in the tissue cells. The oxygen exchange continues until equilibrium occurs on the either sides of the respiratory membrane in the tissue. Hence, the final partial pressure of oxygen in the blood becomes 40 mmHg. The partial pressure of oxygen in the blood increases up to 100 mmHg. The partial pressure of carbon dioxide in the blood is 45 mmHg while that of the alveolar air is 40 mmHg. The final partial pressure of oxygen retains 100 mmHg while the partial pressure of carbon-dioxide shows as 40 mmHg in the blood.