Table 1.

Essential GO terms and their definitions

Compartment	Essential	Definition
	GO term
Centriole	GO:0005814	A cellular organelle, found close to the nucleus in many eukaryotic cells, consisting of a small cylinder with microtubular walls, 300–500 nm long and 150–250 nm in diameter.
Cytoplasm	GO:0005737	All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.
Cytoskeleton	GO:0005856	Any of the various filamentous elements that form the internal framework of eukaryotic cells, and typically remain after treatment of the cells with mild detergent to remove membrane constituents and soluble components of the cytoplasm.
Endoplasmic reticulum	GO:0005783	The irregular network of unit membranes, visible only by electron microscopy, that occurs in the cytoplasm of many eukaryotic cells.
Extracellular	GO:0030198	A process that is carried out at the cellular level which results in the formation, arrangement of constituent parts, or disassembly of an extracellular matrix
Golgi apparatus	GO:0005794	A compound membranous cytoplasmic organelle of eukaryotic cells, consisting of flattened, ribosome-free vesicles arranged in a more or less regular stack. ...
Lysosome	GO:0005764	Any of a group of related cytoplasmic, membrane bound organelles that are found in most animal cells and that contain a variety of hydrolases, most of which have their maximal activities in the pH range 5–6. ...
Chloroplast	GO:0009507	Any of the small, heterogeneous, artifactual, vesicular particles, 50–150 nm in diameter, that are formed when some eukaryotic cells are homogenized and that sediment on centrifugation at 100000 g.
Microsome	GO:0005792	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.
Mitochondrion	GO:0005739	A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. ...
Nucleus	GO:0005634	A small, membrane-bounded organelle that uses dioxygen (O2) to oxidize organic molecules; contains some enzymes that produce and others that degrade hydrogen peroxide (H2O2).
Peroxisome	GO:0005777	The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.
Plasma membrane	GO:0005886	A cellular organelle, found close to the nucleus in many eukaryotic cells, consisting of a small cylinder with microtubular walls, 300–500 nm long and 150–250 nm in diameter. It contains nine short, parallel, peripheral microtubular fibrils, each fibril consisting of one complete microtubule fused to two incomplete microtubules.
Cell wall	GO:0005618	The rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal, and most prokaryotic cells, maintaining their shape and protecting them from osmotic lysis.
Cyanelle	GO:0009842	Plastid type found in Glaucophyta having unstacked thylakoid membranes bearing phycobilisomes; cyanelles are bound by a double membrane and a peptidoglycan layer.
Vacuole	GO:0005773	A closed structure, found only in eukaryotic cells, that is completely surrounded by unit membrane and contains liquid material.
Plastid	GO:0009536	Any member of a family of organelles found in the cytoplasm of plants and some protists, which are membrane-bounded and contain DNA.