Final answer:
All plants and animals begin the process of cellular respiration in the cytoplasm, where glucose is broken down during glycolysis. The process then continues into the mitochondria, ultimately tracing the energy source back to photosynthesis.
Step-by-step explanation:
photosynthesis:
In the context of cellular processes, both animals and plants require energy to carry out their functions. This energy is typically obtained through the process of cellular respiration. Initially, cellular respiration begins in the cytoplasm, where glucose, a simple sugar derived from the food organisms consume, undergoes a series of reactions. This initial stage is known as glycolysis and it breaks down glucose into pyruvate while producing a small amount of ATP (adenosine triphosphate), which is the energy currency of the cell.
The stored energy that all organisms depend upon traces its origins back to the sun and the process of photosynthesis, where plants, certain algae, and cyanobacteria use sunlight to create glucose and oxygen from carbon dioxide and water.