Conjugated Carbohydrates Flashcards

Flashcards for reviewing conjugated carbohydrates, glycolipids, proteoglycans, GPI anchors, and lipopolysaccharides.

Glycolipids

Conjugated carbohydrates with oligosaccharide chains covalently linked to lipid moieties, typically ceramides, found in cellular membranes.

Biochemical Functions of Glycolipids

Markers for cellular recognition, involved in immune responses (e.g., ABO blood group antigens), signal transduction, membrane stability, and pathogen interaction.

Proteoglycans

Conjugated carbohydrates composed of a core protein covalently attached to one or more glycosaminoglycan (GAG) chains.

Proteoglycans Location and Synthesis

Found in the extracellular matrix, providing mechanical support; synthesized in the Golgi apparatus.

Biochemical Functions of Proteoglycans

Contribute to tissue resilience, regulate cell behavior, and act as co-receptors and signal modulators.

Glycosylphosphatidylinositol (GPI) Anchors

Glycolipid structures that tether proteins to the outer leaflet of the plasma membrane in eukaryotic cells, consisting of a phosphatidylinositol lipid, a glycan core and a phosphoethanolamine linker.

Biochemical Functions of Glycosylphosphatidylinositol Anchors

Provide stable membrane anchoring, participate in signal transduction, and direct proteins to specific membrane domains.

Lipopolysaccharides (LPS)

Large glycolipids found in the outer membrane of Gram-negative bacteria, composed of Lipid A, core oligosaccharide, and O-antigen polysaccharide.

Biochemical Functions of Lipopolysaccharides

Stabilizes the outer membrane, activates the innate immune system, and helps bacteria evade immune detection.

Glycosyltransferases

Enzymes that catalyze the transfer of glycosyl residues from a nucleotide sugar to an acceptor molecule, forming a glycosidic bond.

Glycosylation

Process of adding or modifying carbohydrate structures on proteins or lipids, affecting their folding, stability, and function.

Glycosidases

Enzymes that catalyze the hydrolysis of glycosidic bonds, breaking down complex carbohydrates into smaller units.

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