- Periplasmic space
The periplasmic space or periplasm is a space between the inner
cytoplasmic membraneand external outer membraneof Gram-negativebacteria. It may constitute up to 40% of its total cell volume.cite book |author=Otto Holst; Guntram Seltmann |title=The Bacterial Cell Wall |publisher=Springer |location=Berlin |year= |pages= |isbn=3-540-42608-6 |oclc= |doi=] The space contains a loose network of mureinpeptidoglycan chains, as well as a gel containing hydrolytic and degradative enzymes.cite book |author=Kenneth J. Ryan; C. George Ray |title=Sherris Medical Microbiology: An Introduction to Infectious Diseases |publisher=McGraw-Hill Medical Publishing Division |location=New York |year=2004 |pages= |isbn=0-8385-8529-9 |oclc= |doi=] Other enzymes in the gel are involved in various biochemical pathways including peptidoglycan synthesis, electron transport, and alteration of substances toxic to the cell ( xenobiotic metabolism).cite book |author=Klein, Donald W.; Prescott, Lansing M.; Harley, John |title=Microbiology |publisher=McGraw-Hill Higher Education |location=Boston |year=2005 |pages= |isbn=0-07-295175-3 |oclc= |doi=] In some species, the gel also contains beta-lactamase, an enzyme responsible for degrading penicillin. This can be of clinical importance when considering antibiotic resistance.
Gram-positive bacteriahave no equivalent space, the enzymesthey produce which would normally be retained in the periplasmic space of a Gram-negative bacterium are instead secreted into the external environment. These secreted enzymes are referred to as exoenzymes.
* D. White, The Physiology and Biochemistry of Prokaryotes, Oxford University Press, Oxford, 2000, pp. 22.
Wikimedia Foundation. 2010.
Look at other dictionaries:
periplasmic space — (per i plas mik) or periplasm (per ī plazm) The space between the plasma membrane and the outer membrane in gram negative bacteria, and between the plasma membrane and the cell wall in gram positive bacteria … Dictionary of microbiology
periplasmic space — Structureless region between the plasma membrane and the cell wall of Gram negative bacteria … Dictionary of molecular biology
periplasmic space — a zone between the plasma membrane and the outer membrane of the cell wall of gram negative bacteria … Medical dictionary
periplasmic binding proteins — Transport proteins located within the periplasmic space. Some act as receptors for bacterial chemotaxis, interacting with MCPs. Their mode of action is unclear … Dictionary of molecular biology
periplasmic — peri·plas·mic plaz mik adj of, relating to, occurring in, or being the space between the cell wall and the plasma membrane <the periplasmic flagella of spirochetes> * * * peri·plas·mic (per″e plasґmik) around the plasma membrane;… … Medical dictionary
Trehalase — protein Name=trehalase (brush border membrane glycoprotein) caption= width= HGNCid=12266 Symbol=TREH AltSymbols= EntrezGene=11181 OMIM=275360 RefSeq=NM 007180 UniProt=O43280 PDB= ECnumber=22.214.171.124 Chromosome=11 Arm=q Band=23.3… … Wikipedia
L-form bacteria — Transmission electron micrograph of L form Bacillus subtilis. The cells lack the electron dense cell wall of normal bacteria. Scale bar is 500 nanometers. L form bacteria, also known as L phase bacteria, L phase variants, and cell wall deficient… … Wikipedia
Bdellovibrio — Taxobox color = lightgrey name = Bdellovibrio regnum = Bacteria phylum = Proteobacteria classis = Delta Proteobacteria ordo = Bdellovibrionales familia = Bdellovibrionaceae genus = Bdellovibrio species = B. bacteriovorus binomial = Bdellovibrio… … Wikipedia
Inner membrane — The inner membrane is the biological membrane (phospholipid bilayer) of an organelle or Gram negative bacteria that is within an outer membrane. In eukaryotic cells, this inner membrane is present within the nuclear envelope, mitochondria and… … Wikipedia
Photosynthetic reaction centre — A photosynthetic reaction center is a complex of three types of protein that is the site where molecular excitations originating from sunlight are transformed into a series of electron transfer reactions. The reaction center proteins bind… … Wikipedia