During cellular respiration what is the direct source of the energu used in the cells of consumers?

Consumers use chemical energy from the chemical bonds within organic molecules such as carbohydrates, lipids,  and amino acids.

Explanation:

Heterotrophs are consumers; they ingest or absorb organic matter (lipids, carbohydrates, proteins, etc.)  made by autotrophs or producers for their energy consumption. Autotrophs include plants, bacteria, and other photosynthesizing organisms, while heterotrophs include animals, fungi, protists, and bacteria.

Heterotrophs obtain energy from food through the process of cellular respiration. For instance, during aerobic respiration in mitochondria, they break down sugars in the form of glucose into carbon dioxide and water to obtain energy in the form of ATP or adenosine triphosphate.

aerobic respiration:      C6H12O6+ 6 O2 → 6 CO2 + 6 H2O + ≅38 ATP

                                      glucose+ oxygen →  carbon dioxide+ water+ energy