Autotrophs are the essential organisms as they produces the food for them as well as for the consumers. This is possible as they can carry out the process of photosynthesis. They uses the light energy provided by the sun and thereby converts it into biomass.
So, these biomass is found to be in maximum amount at the base of the trophic level and it gradually decreases as the trophic level increases.
Thus, the autotrophs stores greater energy as well as greater biomass in the lower trophic level.
Cellular respiration is the process of conversion of food energy (glucose) into chemical energy (ATP). Oxygen and glucose are the reactants in the chemical reaction of this process and carbon dioxide and water are the products.