A eukaryotic cell (left) has membrane-enclosed DNA, which forms a structure called the nucleus (located at center of the eukaryotic cell; note the purple DNA enclosed in the pink nucleus). A typical ...

Many viruses, including that perennial winter affliction, the influenza virus, are protected by a lipid membrane on loan from the host cell. The fusion proteins on the surface of the membrane are ...

Prokaryotic cells, which include all bacteria and archaea, are ancient, and relatively simple compared to eukaryotic cells, which are found in fungi, plants, and animals. Scientists have long sought ...

The chemical reactions on which life depends need a place to happen. That place is the cell. All the things which biology recognises as indisputably alive are either cells or conglomerations of cells ...