The cell respiration portion of the process allows plants to grow, move, etc. Producers produce more glucose and oxygen than they use during cell respiration. If this was not the case, there would be no energy available for consumers. If plants did not use some of the carbon captured during photosynthesis to create themselves, etc. Consumers, detritus feeders and decomposers use energy captured by the producers.
Cell respiration is the process by which consumers, detritus feeders and decomposers obtain energy.
In this process carbon dioxide and water are released and energy is used.