Organelles
Every organelle of the human cell: what it is, what is known about it with the source beside it, and a digital copy that each cell site reuses in its own colours. 18 of 18 written so far.
Nucleus The compartment that holds the genome, wrapped in a double envelope whose pores are the only way in or out. Nucleolus The ribosome factory: three nested components, no membrane, and a size and number that depend on which cell you are looking at. Nuclear envelope Two membranes with a space between them, pierced by the only route in or out, and braced against the cytoskeleton so the nucleus can be pushed around without tearing. Plasma membrane Two leaflets that are not the same, over an actin meshwork that divides the surface into compartments. Rough ER The ribosome-studded sheets of the endoplasmic reticulum, where secreted and membrane proteins are made. Smooth endoplasmic reticulum The tubular network with no ribosomes on it: lipid and steroid synthesis, calcium store, and where the hepatocyte keeps its drug-metabolising P450. Golgi The stack of flattened cisternae where proteins and lipids are modified, sorted and sent on. Mitochondrion A double-membraned organelle whose folded inner membrane carries oxidative phosphorylation, and which keeps a genome of its own. Lysosome The acidic compartment that digests what the cell takes in or breaks down, and reports on the state of metabolism while it does. Peroxisome A single-membrane body that runs beta-oxidation of very long chain fatty acids and destroys the hydrogen peroxide it makes. Ribosome The machine that reads the message and builds the protein, assembled from two subunits made in the nucleolus. Proteasome Four stacked rings of seven subunits each, capped at both ends, carrying three different cutting specificities in one machine. Cytoskeleton Three filament systems at three diameters: actin at 7 nm, the intermediate filament at 10, the microtubule at 25. Centrosome Two centrioles at right angles, each a cylinder of nine triplet microtubules around a cartwheel. Cilia and flagella Nine doublets around a central pair, with the motor on one side and the signal line running to the middle. The human body carries four kinds of it, not two. Endosomes and vesicles Not one body but a route. The sorting station changes its marker protein rather than handing cargo to a different organelle, and the coat at the start of the route is not always a round cage. Lipid droplet Neutral lipid under a single phospholipid monolayer, not a bilayer, because what it encloses is oil rather than water. Autophagosome The compartment the cell builds in order to destroy it. Bounded by two membranes, assembled from lipid it borrows, and identified by a marker that is not exclusive to it.