Question

Write a note on respiration in animals.

Answer 1

Respiration:

It is a metabolic process that occurs within the cells of organisms.

Types of respiration in animals:

1. Simple diffusion: Occurs via the cell membrane in simple unicellular creatures like Amoeba.
2. Skin: Earthworms and other soil animals use their skin to absorb oxygen from the air and expel carbon dioxide.
3. Gills: They are found in aquatic creatures such as fish, prawns, and mussels. They extract oxygen from water and remove carbon dioxide from the body.
4. Spiracles: This is the respiratory organ of insects such as grasshoppers, cockroaches, houseflies, and mosquitos as tiny pores on their bodies and air tubes called tracheae.
5. Lungs: These are the respiratory organs of land creatures such as humans, birds, lizards, dogs, and frogs. Frogs can breathe through both their lungs and their skin.
6. Anaerobic respiration: It is the process of respiration performed in low levels of oxygen. In this process, glucose is broken down into carbon dioxide, ethyl alcohol, and energy.
7. Aerobic respiration: It is the process of respiration performed in the presence of oxygen. In this process, glucose is broken down into carbon dioxide and water.
8. The three stages of aerobic respiration are -

1. Glycolysis: It is the metabolic process of producing energy by breaking down glucose into pyruvic acid.
2. Citric acid cycle: It is the series of biochemical reactions taking place in the mitochondria in which acetyl CoA is oxidized and ADP is converted to ATP.
3. Oxidative phosphorylation:⁠⁠⁠⁠⁠⁠⁠ It is the process of synthesis of ATP brought about by the movement of electrons through the electron transport chain of the mitochondria.