I think it's when glycogen turns glycogen into glucose and vice versa. Not too sure though.
Plants use nitrogen for <u><em>making protein</em></u> since proteins are rich in it because of the amino group of the amino acids.
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Sweat glands is the major function in thermoregulation.
An analogy that can link with the process of respiration can be a factory. For example, the way that the factory processes raw goods to make manufactured goods is similar to how the respiratory system takes in molecules and breaks it down into energy.
