Why is there always aloss of chemical energy with each step in a food chain?

In a food chain, energy is transferred from one trophic level to the next, but not all energy is converted into biomass. A significant portion of chemical energy is lost as heat through metabolic processes such as respiration, digestion, and movement. Additionally, some energy is lost through waste products and inefficiencies in energy transfer, typically around 90% of the energy is lost at each step, leading to less energy available for the next level. This loss of energy limits the number of trophic levels in an ecosystem.