Organelles are specialized subunits within a cell that perform specific functions. In metabolic activities, the mitochondria are often referred to as the "powerhouses" of the cell because they generate ATP through oxidative phosphorylation. The endoplasmic reticulum is involved in protein and lipid synthesis, while the Golgi apparatus modifies, sorts, and packages proteins and lipids for secretion or for use within the cell. Lysosomes contain digestive enzymes that break down macromolecules, playing a key role in cellular waste disposal and energy release.
