Carbohydrates, fats and proteins are all fuels that can be used to carry out the process of respiration. Glucose is also commonly used to examine the pathways and reactions involved in respiration.
Respiration is the process in which cells gain the energy they need to fuel cell activities. The process is considered an exothermic one, which means the entire process can be broken down into a bunch of smaller ones as it occurs in the body. In aerobic respiration, oxygen is needed in order to generate ATP, but carbohydrate, fats and proteins can also be used as reactants during the process.