spongin การใช้

• True spongin is found only in members of the class Demospongiae.
• Researchers have found over 100, 000 types of spongin.
• Spicule density is high with little to no spongin present.
• More commonly, the mesohyl is stiffened by spicules, by spongin fibers or both.
• They are bleached and marketed; the spongin gives the sponge its softness and absorbency.
• Spongin gives a sponge its flexibility.
• Sponge skeletons consist of either spongin or calcareous and siliceous spicules with some collagen molecules interspersed.
• They are distinguished by a siliceous skeleton of two and four rayed spicules and contain the protein spongin.
• Demosponges use spongin, and in many species, silica spicules and in some species, calcium carbonate exoskeletons.
• Bath sponges can be defined as any sponge species possessing only spongin fibers  which are springy fibres made from collagen protein.
• Spongocytes make gemmules by wrapping shells of spongin, often reinforced with spicules, round clusters of archeocytes that are full of nutrients.
• In species of sponges that use spongin instead of calcaerous and silicaceous spicules, the sclerocytes are replaced by spongocytes, which secrete spongin skeletal fibres.
• In species of sponges that use spongin instead of calcaerous and silicaceous spicules, the sclerocytes are replaced by spongocytes, which secrete spongin skeletal fibres.
• They are generally characterized by concentric layers of fibers containing spongin ( a collagen-like material ), and by large flagellated chambers that open directly into the exhalant canals.
• However Janussen, Steiner and Zhu ( 2002 ) opposed this view, arguing that : spongin does not appear in all Porifera, but may be a defining feature of the demosponges; the silica-based spines of demosponges are filter-feeders.
• Along with the Dictyoceratida, it is one of the two orders of demosponges that make up the keratose or " horny " sponges, in which a mineral skeleton is minimal or absent and a skeleton of organic spongin-containing fibers is present instead.
• In both Homoscleromorpha and Eumetazoa layers of cells are bound together by attachment to a carpet-like basal membrane composed mainly of " type IV " collagen, a form of collagen not found in other sponges  although the spongin fibers that reinforce the mesohyl of all demosponges is similar to " type IV " collagen.
• :: As for halogens in amino acids-I was going to say not likely-since most examples I know of tend to appear to be the result of electrophilic attack on double bonds eg terpene like compounds etc . . but no : halogenated tyrosines found in marine animals-spongin in sponges and gorgonin in Gorgonians this time-again marine creatures . talk ) 19 : 49, 18 June 2010 ( UTC)