FBICH 410 1st Edition Lecture 16Outline of Last Lecture - Disaccharides- PolysaccharidesOutline of Current Lecture - Polysaccharideso Pepditoglycan- Bacterial cell wall component Made of n-acetylmuramic acid (NAM) and N-aceytlglucosamine (NAG) Gram positive have pentaglycine crosslink while gram-negative hace direct crosslink Gram positive have thick cell walls while gram negative hace thinner and are covered by an outer membrane Gram negative are more antibiotic resistant than gram-positive Have peptide chain: L-ala;D-Glu;L-Lys;D-Alao Antibiotics= pencillin binds and inactivates the enzyme that catalyzes the crosslinking of peptidoglycan B-lactamase can be secreted by bacteria causing penicillin resistance Vancomycin binds to the D-ala-D-ala sequence in peptide chain inhibiting crosslinkingo Glycoproteins- membrane associated and secreted proteins of Eukarya typically are glycosylated Oligosaccharides attached to proteins via N-glycosidic or O-glucosidic- O-linked are synthesized in Golgi and are created by serial additions to the monosaccharide- Glycosylation occurs at specific 2ary and 3ary structures- Ser and Thr are not part of AA seq N-linked- amide nitrogen of an Asn residue with sequence: ASN-X-SER or ASN-X-THR- Occurs cotranslationally and are glycosolated then processed to give a common core oligosaccharide - Very common for proteins and creates many functions such as protein lifetime and traffickingo Glycolipids and lipopolysaccharides Sialic acid= found at termini of most oligosaccharide chains of glycoproteins/glycolipids- Acts as a ligand for sugar binding proteins- ie virus, bacteria- Cleavage of acid exposes galctose which is required for protein turnoverThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Proteoglycans- glucosaminoglycans generally linked to extracellular proteins to form proetoglycans forms connective tissues Cartilage matrix proteoglycan- very hydrated so when compressed releases water and when released absorbs watero Protein carbohydrate interaction- lectins= proteins binding carbs Lectins decipher sugar code and serve as cell-cell recognition, signaling, and for adhesion Selectins allow leukocytes to attach to surface of endothelial cells Lectin-oligosaccharide interactions are very specific Lectin receptors recognize enyzmes with mannose-6-phosphate and target for delivery to lysosomes- I-cell disease when this works defectively C-reactive protein- prevents inflammation damage Influenze hemagglutin (HA)- HA binds to sialic acid which triggers formation of endosome Ricin- biochemical warfare agent- Obtained from castor oil plant- has lectin that binds galactosyl and enables protein to enter cell and also contains a N-glycosidase that causes cleavage of rRNA resulting in cell death Blood and Carb- O antigen, A antigen, B antigen - Lipids- soluble in organic solventso Form bilayer for membranes, Serve as energy storage through hydrocarbon sidechains, Allow for intra and intercellular signaling o Classification: fatty acid, triacylglycerols, glycerophospholipids, sphingolipids, steroidso Fatty acids- carboxylic acids with long hydrocarbon groups- typically C16-C18 Saturated- pack tightly and are more rigid Unsaturated- pack less-orderedly and with more motion- double bonds have cis configuration; 1st double bond typ. Between C9-C10 Nomenclature: C18:1 n-3 18Carbons and 1 double bond on 3rd carbon Omega fatty acids aka N-fatty acids- C16:1n-3 or C20:5 n-3 Must be able to draw a saturated and unsaturatedfatty acid using zig-zag notation, showing carboxylic acid and cis bond- stearic acid and oleic acid Must be able to draw omega fatty acids- stearic acid (C18:0) oleic acid (c18:1 N-9), linoleic acid (c18:2 n-9,12), and alpha-linolenic acid (C18:3 n-9,12,15)o Triacylglycerols/Triglycerides Fatty acid triesters of glycerol- Glycerol binded to 3 fatty acids Usually contain different types of fatty acid residues Melting temps- animal fats have high percent saturation of fatty acids; plant fats have high percent of unsaturated; melting temp will cary based on degree saturation and chain length Triacylglycerols fxn as energy reservoirs- human can survive 2-3 months on fat- Also insulate- Olestra- carb based fat substitute- inhibits absorption of vitamins and nutrients- Saponification- formation of triacylglycerols in soaps Non polar lipids= energy storage Polar= bilayerso Finish lipids next class with glycerophospholipids, sphingolipids, and