Answer:
Respiration is a process in which energy is released due to the breakdown of glucose molecules with the addition of oxygen forming carbondioxode, water and energy in the form of Adenine tri phosphate (ATP). This process also occurs in the absence of oxygen but then low amount of energy is generated. This process occurs in mitochondria of the cell. The energy which is produced during respiration is used by the cell in different processes and activities such as movement, exercise and thinking etc.