"A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent [goid 5634] [evidence IEA]; All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures [goid 5737] [pmid 11530860] [evidence IDA]; A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration [goid 5739] [evidence IEA]; A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration [goid 5739] [pmid 9027314] [evidence IDA]; The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope [goid 5741] [pmid 9027314] [evidence IDA]; The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope [goid 5741] [pmid 11463392] [evidence EXP]; The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope [goid 5741] [pmid 10198631] [evidence EXP]; The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope [goid 5741] [pmid 12624108] [evidence EXP]; The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope [goid 5741] [pmid 1453000] [evidence TAS]; The irregular network of unit membranes, visible only by electron microscopy, that occurs in the cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The ER takes two forms, rough (or granular), with ribosomes adhering to the outer surface, and smooth (with no ribosomes attached) [goid 5783] [evidence IEA]; The lipid bilayer surrounding the endoplasmic reticulum [goid 5789] [evidence IEA]; That part of the cytoplasm that does not contain membranous or particulate subcellular components [goid 5829] [evidence IEA]; Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins [goid 16020] [evidence IEA]; Penetrating at least one phospholipid bilayer of a membrane. May also refer to the state of being buried in the bilayer with no exposure outside the bilayer. When used to describe a protein, indicates that all or part of the peptide sequence is embedded in the membrane [goid 16021] [evidence IEA]; Either of the lipid bilayers that surround the nucleus and form the nuclear envelope; excludes the intermembrane space [goid 31965] [pmid 1502141] [evidence IDA]"