Eukaryotic cells contain numerous internal compartments. Membrane bound organelles allowing for very specific functions to occur within microenvironments. Protected from both the cytoplasmic interior and the extracellular surroundings. For instance, the nucleus requires controlled conditions for precise regulation of the genes inside. Therefore, its surrounded by a double membrane. The nuclear envelope with pores to control what molecules can enter and leave like mRNA's. Furthermore, some proteins require an oxidative environment and must be isolated from the cytosol which is reductive, thus, ribosomes produce these proteins within the endoplasmic reticulum where they can also undergo critical modifications. Subsequent movements even happen within small chemical microcosms called vesicles while en route to their final destinations. Other organelles, such as peroxisomes, provide protection from their own damaging byproducts, like hydrogen peroxide, by sequestering enzymes that convert toxic compounds into harmless molecules, such as water. Similarly, lysosomes segregate enzymes, but for a different reason. To safeguard digestive reactions that require a much lower PH than the cytoplasm harbors. Mitochondria also have acidic interiors between their two membranes which help produce energy. Overall, eukaryotic compartmentalization supports actions that would otherwise be incompatible if carried out simultaneously without some form of containment.