The general name given to the membrane-bound structures within a eukaryotic cell (the cells that have nuclei) that perform specific functions necessary for cell survival, growth, or reproduction. Examples include Golgi bodies, lysosomes, mitochondria, chloroplasts, endoplasmic reticulum, vacuoles, and vesicles.ost of the ATP in a cell is made in the mitochondria, the cell's powerhouse. ATP is a coenzyme (the-ase in the name gives it away) and a strong reducing agent, or electron donor, that acts as the principal energy carrier in the cell.