Endoplasmic Reticulum: A network of membranous tubules within the cytoplasm of a eukaryotic cell, involved in protein and lipid synthesis.
Golgi Apparatus: A complex of vesicles and folded membranes within the cytoplasm, involved in secretion and intracellular transport.
Autophagy: The process by which cells recycle their own components to provide the necessary building blocks for maintaining cellular functions and adapting to changing conditions.