Polysaccharides:- Glycolipids and Lipopolysaccharides Are Membrane Components

Glycoproteins are not the only cellular components that bear complex oligosaccharide chains; some lipids, too, have covalently bound oligosaccharides. Gangliosides are membrane lipids of eukaryotic cells in which the po lar head group, the part of the lipid that forms the outer surface of the membrane, is a complex oligosaccharide containing sialic acid (Fig. 7–9) and other monosaccha ride residues. Some of the oligosaccharide moieties of gangliosides, such as those that determine human blood groups , are identical with those found in certain glycoproteins, which therefore also contribute to blood group type determination. Like the oligosaccharide moieties of glycoproteins, those of membrane lipids are generally, perhaps always, found on the outer face of the plasma membrane. Lipopolysaccharides are the dominant surface feature of the outer membrane of gram-negative bacteria such as Escherichia coli and Salmonella typhimurium. These molecules are prime targets of the antibodies produced by the vertebrate immune system in response to bacterial infection and are therefore important determinants of the serotype of bacterial strains (serotypes are strains that are distinguished on the ba sis of antigenic properties). The lipopolysaccharides of S. typhimurium contain six fatty acids bound to two glucosamine residues, one of which is the point of attachment for a complex oligosaccharide (Fig. 7–32). E. coli has similar but unique lipopolysaccharides. The lipopolysaccharides of some bacteria are toxic to hu mans and other animals; for example, they are responsible for the dangerously lowered blood pressure that occurs in toxic shock syndrome resulting from gram negative bacterial infections.

اخر الاخبار

اخبار العتبة العباسية المقدسة

وفد العتبة العباسية المقدسة يزور قضاء آمرلي ويشيد بجهود أهاليه في دعم الشعبين الإيراني واللبناني

قسم التطوير يقيم دورة عن أخلاقيات المهنة ضمن البرنامج التأهيلي لمنتسبي العتبة العباسية المقدسة الجدد

شعبة التوجيه الديني النسوي تحيي ذكرى ولادة الإمام الرضا (عليه السلام)

في ذكرى ولادته.. قسم الشؤون الدينية يستذكر فضائل الإمام الرضا (عليه السلام)

المزيد

الآخبار الصحية

أطعمة مفيدة وأخرى ضارة للأسنان

دراسة تكشف تأثيرا خفيا لتناول المانجو والأفوكادو معاً

لكسر الإدمان وحماية الصحة.. بدائل طبيعية للسكر المعالج

قرار تاريخي في بريطانيا.. منع التدخين تماما لمواليد 2008

المزيد

الآخبار التكنلوجية

10 أخطاء يومية تدمّر سيارتك ومحركها بصمت: كيف تحافظ عليها؟

روسيا.. تطوير هيدروجيل حيوي لتحسين كفاءة الري وتنظيم رطوبة التربة

حل لغز البرق البركاني ؟

تطبيق ذكاء اصطناعي يتصفح الإنترنت ومنصات التواصل بدلا عنك !

المزيد

مواضيع ذات صلة

Nucleic Acid Structure:- DNA Stores Genetic Information

Carbohydrates as Informational Molecules: The Sugar Code:- Lectin-Carbohydrate Interactions Are Very Strong and Highly Specific

Carbohydrates as Informational Molecules: The Sugar Code:- Lectins Are Proteins That Read the Sugar Code and Mediate Many Biological Processes

Polysaccharides: - Glycoproteins Have Covalently Attached Oligosaccharides

Polysaccharides:- Proteoglycans Are Glycosaminoglycan-Containing Macromolecules of the Cell Surface and Extracellular Matrix

Polysaccharides:- Glycosaminoglycans Are Heteropolysaccharides of the Extracellular Matrix

Polysaccharides:- Bacterial and Algal Cell Walls Contain Structural Hetero polysaccharides

Polysaccharides: -Steric Factors and Hydrogen Bonding Influence Homopolysaccharide Folding

Polysaccharides:- Some Homopolysaccharides Serve Structural Roles

Polysaccharides:- Some Homopolysaccharides Are Stored Forms of Fuel

Monosaccharides and Disaccharides:- Disaccharides Contain a Glycosidic Bond

Monosaccharides and Disaccharides:- Monosaccharides Are Reducing Agents