All organisms are made of small microscopic units called cells. A cell is the smallest structural and functional unit of an organism. Each cell of an organism performs certain functions such as nutrition, transportation, excretion and reproduction. To perform these functions, the cell needs energy. Even when we are eating, sleeping or reading we require energy. The food has stored energy, which is released during respiration. Therefore, all living organisms respire to get energy from food.
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Cellular respiration : Cellular respiration takes place in the cells of all organisms. It is an intracellular process in which glucose is oxidised and the energy is used to make ATP (adenosine triphosphate). It consists of many separate enzymatic reactions.
Cellular respiration are of two types : Aerobic and Anaerobic respiration.
Glucose + oxygen → Carbon dioxide + Water + Energy
Glucose (without the use of oxygen) → Alcohol + Carbon dioxide + Energy
Anaerobic Respiration in Muscle Cells :
Glucose in muscle cells (without the use of oxygen) → Lactic acid + Energy
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