Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Cell Membrane

  • Carlos Briones
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_1235-3

Synonyms

Definition

The cell membrane is the boundary that envelops all cells and provides a semipermeable barrier for their separation from the extracellular environment. It is constituted by a 5–8-nm-thick lipid bilayer – mainly composed of amphiphilic phospholipids – in which membrane proteins are interspersed. The cell membrane is involved in different cellular processes including active and passive traffic of substances, signal transduction, and cell adhesion and fusion. In addition to the cell membrane, inside the eukaryotic cytoplasm, there are membrane-enclosed organelles. These specialized compartments include the nucleus, mitochondria, plastids, Golgi apparatus, vacuoles, vesicles, lysosomes, peroxisomes, and endoplasmic reticulum. Mitochondria, present in almost all eukaryotes, and plastids, present in photosynthetic eukaryotes, are double-membrane organelles, a feature indicative of their endosymbiotic origin. Bacteriaand archaea lack...

Keywords

Cell Membrane Endoplasmic Reticulum Bioorganic Chemistry Lipid Bilayer Golgi Apparatus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Centro de Astrobiología (CSIC/INTA)Consejo Superior de Investigaciones CientíficasTorrejon de Ardoz MadridSpain