BIOL 302 1st Edition Lecture 23Outline of Last Lecture I. MetabolismOutline of Current Lecture I. Carbohydrate StructureII. IsomersCurrent LectureI. Representing CarbohydratesII. Sugars: Isomeric formsA. IsomersB. constitutional isomersC. StereoisomersThese 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.III. EnantiomersA. Only one of these will be a substrate for an enzyme; not both R- rectus or right S- sinister or lefIV. Enantiomers and IsomersV. The simplest sugars have 3 carbonsA. 2 families of sugars, based on structureVI. FormulasVII. Ball and stick VIII. IsomersIX. D-AldosesX. D-aldosesXI. Clicker Question: Which of the following are true?\A. These molecules are isomersB. These molecules are diastereomersC. These all have the same molecular wtD. These are all reducing sugarsE. All of the aboveXII. D-riboseXIII. Six-carbon sugars you should knowXIV. Clicker Question: Are these aldoses or ketoses?, Are they pentoses or hexoses?A. aldoses; pentosesB. ketoses; pentosesC. aldoses; hexosesD. ketoses; hexosesXV. D-mannoseXVI. Monosaccharide NomenclatureA. Common ring structures1. pyranose: 6 atoms2. furanose: 5 atomsXVII. Pyranose ring structureA. Glucose can take two formsXVIII. A hemiacetalA. forms afer C-5 (-OH) attacks C-1 aldehyde group’s OXIX. A hemiketalA. forms afer C-5 (-OH) attacks C-2 ketone group’s O; two anomeric forms (α andβ)ketoseXX. 5-membered furanose A. fructose derivativesB. free fructose in soln1. found in honey; heat-sensitiveXXI. Chair and boat conformations exist for 6-carbon sugarsA. β-D-glucoseB. (Lef) All non-H atom on the ring are equatorial. XXII. Clicker Question: Compare β glucose to α glucose, which is more stable?A. alphaB. betaC. they are the sameXXIII. Furanose rings are not planarXXIV. Aldehyde groupA. the open chain form of glucose can reduce copperXXV. Glucose’s open-chain aldehydeA. can also react with hemoglobin in the bloodXXVI. Glycosidic bondsA. join the anomeric carbon atom of a monosaccharide to N, S, O atoms of other molecules N-glycosidic bondXXVII. MonosaccharidesA. can be modified at positions other than the anomeric carbonB.XXVIII. MonosaccharidesA. can be linked to form disaccharidesXXIX. Common DisaccharidesA. Maltose is the repeating unit of amyloseB. Lactose “milk sugar”– Broken down by lactaseC. Sucrose is the major sugar produced by plants1. – it is a non-reducing sugar XXX. PolysaccharidesA. composed of many monosaccharide unitsB. Different polysaccharides are characterized by:1. – the monosaccharides involved2. – the linkages used (which carbons, a or b)C. Reducing ends can still open; other sugars remain in ring formXXXI. StarchA. a storage polysaccharide in plantsB. Natural starches are mixtures of amylose (10-20%) and amylopectin (80-90%)1. Amylose (α-1,4 glucoselinks)2. – Amylopectin (α-1,4 glucose links with α-1,6 branches3. once every 30 residues)4.XXXII. The animal storage polysaccharide glycogenA. Contains glucose chains joined by α-1,4 and α-1,6 linkagesXXXIII. Structural PolysaccharidesA. Cellulose is a β1,4 glucose polymer1. the most abundant natural polymer in the world2. – fibril structure3. – indigestible by4. AnimalsXXXIV. Glycogen’s branchedA. structure is better for breakdown of stored
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