The molecule necessary for respiration to occur in both plants and animals is NADH or Nicotinamide Adenine Dinucleotide Hydride. This compound is necessary for cellular development and energy production: It's crucial to produce energy from the food one consumes. It's also the principal carrier of electrons in the energy-producing process in the cells.
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Cellular respiration requires energy from an organic source (ie- glucose and oxygen). Without these, the reactions cannot take place. Oxygen is also needed. It acts as the final electron acceptor in electron transport.
