DOCSLIB.ORG

Carbohydrates Hydrates of Carbon: General Formula Cn(H2O)N Plants

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Carbohydrates Hydrates of Carbon: General Formula Cn(H2O)N Plants Chapter 25: Carbohydrates hydrates of carbon: general formula Cn(H2O)n Plants: photosynthesis hν 6 CO2 + 6 H2O C6H12O6 + 6 O2 Polymers: large molecules made up of repeating smaller units (monomer) Biopolymers: Monomer units: carbohydrates (Chapter 25) monosaccharides peptides and proteins (Chapter 27) amino acids nucleic acids (Chapter 28) nucleotides 246 25.1: Classification of Carbohydrates. I. Number of carbohydrate units monosaccharides: one carbohydrate unit (simple carbohydrates) disaccharides: two carbohydrate units (complex carbohydrates) trisaccharides: three carbohydrate units polysaccharides: many carbohydrate units CHO H OH HO HO HO H HO HO O HO O H OH HO HO OH HO H OH OH CH2OH HO HO HO O HO O HO HO O HO HO O HO HO HO O O O O O HO HO O HO HO HO O O HO HO HO OH O 247 126 II. Position of carbonyl group at C1, carbonyl is an aldehyde: aldose at any other carbon, carbonyl is a ketone: ketose III. Number of carbons three carbons: triose six carbons: hexose four carbons: tetrose seven carbons: heptose five carbons: pentose etc. IV. Cyclic form (chapter 25.6 and 25.7) CHO CHO CHO CHO CH2OH H OH HO H H OH H OH O CH2OH H OH H OH HO H HO H CH2OH H OH H OH H OH CH2OH H OH H OH CH OH 2 CH2OH glyceraldehyde threose ribose glucose fructose (triose) (pentose) (tetrose) (hexose) (hexose) 248 (aldohexose) (ketohexose) 25.2: Fischer Projections and the D-L Notation. Representation of a three-dimensional molecule as a flat structure. Tetrahedral carbon represented by two crossed lines: horizontal line is coming vertical line is going back out of the plane of the behind the plane of the page (toward you) paper (away from you) substituent carbon (R)-(+)-glyceraldehyde CHO CHO CHO H OH H OH H C CH2OH HO CH2OH CH2OH (S)-(-)-glyceraldehyde CHO CHO CHO HO H HO H HO C CH2OH H CH2OH CH2OH 249 127 before the R/S convention, stereochemistry was related to (+)-glyceraldehyde CHO CHO H OH HO H CH2OH CH2OH D-glyceraldehyde L-glyceraldehyde R-(+)-glyceraldhyde S-(-)-glyceraldhyde (+)-rotation = dextrorotatory = D (-)-rotation = levorotatory = L D-carbohydrates have the -OH group of the highest numbered chiral carbon pointing to the right in the Fisher projection as in R-(+)-glyceraldhyde For carbohydrates, the convention is to arrange the Fischer projection with the carbonyl group at the top for aldoses and closest to the top for ketoses. The carbons are numbered from top to bottom. 250 Carbohydrates are designated as D- or L- according to the stereochemistry of the highest numbered chiral carbon of the Fischer projection. If the hydroxyl group of the highest numbered chiral carbon is pointing to the right, the sugar is designated as D (Dextro: Latin for on the right side). If the hydroxyl group is pointing to the left, the sugar is designated as L (Levo: Latin for on the left side). Most naturally occurring carbohydrates are of the D-configuration. 1 CHO 1 H 2 OH CHO 3 2 HO H H OH 3 H 4 OH HO H highest numbered highest numbered 5 HO 4 H "chiral" carbon H OH "chiral" carbon 5 CH2OH 6 CH2OH D-Glucose L-Arabinose CHO HO H CHO H OH HO H HO H H OH highest numbered highest numbered H OH "chiral" carbon HO H "chiral" carbon CH OH CH2OH 2 251 L- glucose D-Arabinose 128 25.3: The Aldotetroses. Glyceraldehyde is the simplest carbohydrate (C3, aldotriose, 2,3-dihydroxypropanal). The next carbohydrate are aldotetroses (C4, 2,3,4-trihydroxybutanal). aldotriose CHO CHO H OH HO H CH2OH CH2OH D-glyceraldehyde L-glyceraldehyde aldotetroses 1CHO 1 CHO 2 HO 2 H highest numbered H OH highest numbered 3 3 "chiral" carbon H OH HO H "chiral" carbon 4 4 CH2OH CH2OH D-erythrose L-erythrose CHO CHO HO H H OH highest numbered highest numbered HO H "chiral" carbon H OH "chiral" carbon CH2OH CH2OH D-threose L-threose 252 25.4: Aldopentoses and Aldohexoses. Aldopentoses: C5, three chiral carbons, eight stereoisomers CHO CHO CHO CHO H OH HO H H OH HO H H OH H OH HO H HO H H OH H OH H OH H OH CH2OH CH2OH CH2OH CH2OH D-ribose D-arabinose D-xylose D-lyxose Aldohexoses: C6, four chiral carbons, sixteen stereoisomers CHO CHO CHO CHO CHO CHO CHO CHO H OH HO H H OH HO H H OH HO H H OH HO H H OH H OH HO H HO H H OH H OH HO H HO H H OH H OH H OH H OH HO H HO H HO H HO H H OH H OH H OH H OH H OH H OH H OH H OH CH2OH CH2OH CH2OH CH2OH CH2OH CH2OH CH2OH CH2OH D-allose D-altrose D- glucose D-mannose D-gulose D-idose D-galactose D-talose 253 129 Manipulation of Fischer Projections 1. Fischer projections can be rotate by 180° (in the plane of the page) only! CHO CH2OH CHO CH2OH 180 ° H OH HO H 180 ° HO H H OH CH2OH CHO CH2OH CHO (R) (R) (S) (S) 180° 180° Valid Valid Fischer Fischer projection projection 254 a 90° rotation inverts the stereochemistry and is illegal! 90 ° CHO OH H OH ! OHC CH2OH CH2OH H (R) (S) 90 ° This is not the correct convention 90° for Fischer projections Should be projecting toward you Should be projecting away you This is the correct convention for Fischer projections and is the enantiomer 255 130 2. If one group of a Fischer projection is held steady, the other three groups can be rotated clockwise or counterclockwise. hold steady CHO CHO H OH HO CH2OH CH2OH H (R) (R) CHO H HO H OHC OH hold steady CH2OH CH2OH (S) (S) 120° 120° hold hold steady steady hold steady 120° 120° hold hold 256 hold steady steady steady Assigning R and S Configuration to Fischer Projections 1. Assign priorities to the four substitutents according to the Cahn-Ingold-Prelog rules 2. Perform the two allowed manipulations of the Fischer projection to place the lowest priority group at the top or bottom. 3. If the priority of the other groups 1→2→3 is clockwise then assign the carbon as R, if priority of the other groups 1→2→3 is counterclockwise then assign the center as S. 2 place at the top 4 CO2H H 1 H2N H 4 2 HO2C NH2 1 hold steady CH3 CH3 rotate other 3 3 three groups counterclockwise 1-2-3 counterclockwise = S 2 4 2 CO2H H CO2H 4 1 2 H NH2 1 H2N CO2H H2N CH3 CH3 1 3 CH3 H 3 3 4 1-2-3 clockwise = R 257 131 Fischer projections with more than one chiral center: 1 CHO CHO 2 HO H HO H 3 H OH H OH 4 CH2OH CH2OH Threose 2 CHO H 4 1 2 1 2 4 2 HO H OHC S OH 3 3 4 H OH 4 H OH 1 Hold Steady 1 3 CH2OH CH2OH 3 (2S, 3R) 4 H 4 H Hold Steady 2 1 2 1 2 2 S OHC OH OHC OH 3 3 4 H OH 1 1 HO CH2OH R 3 CH OH H 2 4 3 258 25.5: A Mnemonic for Carbohydrate Configuration. (please read) 25.6: Cyclic Forms of Carbohydrates: Furanose Forms. O H+ + HO OR2 H , R2OH R2O OR2 + R2OH R1 H (Ch. 17.8) R1 H R1 H hemiacetal acetal O OH OR H + H H H , ROH OH O Ch. 25.13 O cyclic hemiacetal mixed acetal (glycoside) 259 132 In the case of carbohydrates, cyclization to the hemiacetal creates a new chiral center. CHO * H OH H H O O H OH H H * + H H * H OH H H H OH CH2OH OH OH OH OH D-erythrose Converting Fischer Projections to Haworth formulas 260 25.7: Cyclic Forms of Carbohydrates: Pyranose Forms. H H 5 OH 5 H O H O OH H H 4 4 1 H H 1 H H 1 CHO HO HO H 2 2 H 3 H OH 3 3 HO OH OH OH H OH H H H H 1 new chiral 4 5 4 3 2 H OH HO CHO H center 5 H 5 H H H OH OH OH OH 5 H H O H OH H H H 4 H H 1 4 H H 1 D-ribose HO HO 2 OH 3 2 O 3 HO OH OH OH ribopyranose 6 CH OH 2 6 CH OH 5 2 OH 5 H O H O OH H H 4 4 1 1 OH H 1 OH H CHO HO HO H 2 3 2 H 3 H OH 6 H OH 3 H OH HO H HOH C H OH H 2 1 new chiral 5 2 H 4 OH HO 4 3 CHO center 6 CH2OH 6 5 CH2OH 5 HOH2C H H OH H OH OH 5 6 H H O H OH H H H 4 OH H 1 4 OH H 1 D-glucose HO HO 2 OH 3 2 O 3 H OH H OH glucopyranose 261 133 25.8: Mutarotation and the Anomeric Effect. The hemiacetal or hemiketal carbon of the cyclic form of carbohydrates is the anomeric carbon. Carbohydrate isomers that differ only in the stereochemistry of the anomeric carbon are called anomers. Mutarotation: The α- and β-anomers are in equilibrium, and interconvert through the open form.
Load more

Recommended publications
  • Pentose PO4 Pathway, Fructose, Galactose Metabolism.Pptx
    Pentose PO4 pathway, Fructose, galactose metabolism The Entner Doudoroff pathway begins with hexokinase producing Glucose 6 PO4 , but produce only one ATP. This pathway prevalent in anaerobes such as Pseudomonas, they doe not have a Phosphofructokinase. The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) is a biochemical pathway parallel to glycolysis that generates NADPH and pentoses. While it does involve oxidation of glucose, its primary role is anabolic rather than catabolic. There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars. For most organisms, the pentose phosphate pathway takes place in the cytosol. For each mole of glucose 6 PO4 metabolized to ribulose 5 PO4, 2 moles of NADPH are produced. 6-Phosphogluconate dh is not only an oxidation step but it’s also a decarboxylation reaction. The primary results of the pathway are: The generation of reducing equivalents, in the form of NADPH, used in reductive biosynthesis reactions within cells (e.g. fatty acid synthesis). Production of ribose-5-phosphate (R5P), used in the synthesis of nucleotides and nucleic acids. Production of erythrose-4-phosphate (E4P), used in the synthesis of aromatic amino acids. Transketolase and transaldolase reactions are similar in that they transfer between carbon chains, transketolases 2 carbon units or transaldolases 3 carbon units. Regulation; Glucose-6-phosphate dehydrogenase is the rate- controlling enzyme of this pathway. It is allosterically stimulated by NADP+. The ratio of NADPH:NADP+ is normally about 100:1 in liver cytosol.
    [Show full text]
  • A by Fluorous-Tag Assistance Th
    Angewandte Chemie DOI: 10.1002/ange.200704262 Carbohydrate Microarrays Synthesis and Quantitative Evaluation of Glycero-d-manno-heptose Binding to Concanavalin A by Fluorous-Tag Assistance** Firoz A. Jaipuri, Beatrice Y. M. Collet, and Nicola L. Pohl* Herein we report the first use of a quantitative fluorous approach has proven valuable for the probing of other classes microarray strategy to show that the mannose-binding lectin of small molecules.[2] In the case of histone deacetylase concanavalin A (conA), contrary to prevailing belief, actually inhibitors with dissocation constants of less than 0.1s À1, the can accept modifications of the mannose at the C-6 position in hits found by fluorous microarrays were comparable to those the form of glycero-manno-heptoses found on pathogenic found by techniques such as surface plasmon resonance bacteria (Figure 1). The well-known mannose–conA interac- (SPR) and solution-based biochemical assays.[2a] Ideally, of course, the relative quantification of these binding interac- tions could also be carried out within the same fluorous microarray screening format. ConA is a plant lectin that is widely used like antibodies as research tools and diagnostics to identify the presence of specific sugars, such as mannose, on cells;[3] however, in reality the sugar specificities of lectins have not been tested broadly, especially against less readily available carbohydrates. ConA is the most-studied lectin and is usually considered to bind terminal alpha-linked mannose, glucose, and N-acetylglucos- amine. Earlier inhibition data suggest that modifications at the C-3, C-4, and C-6 positions of the d-mannopyranose deter binding to conA.[4] In particular, the loss of the hydroxy group in the C-6 position as in 6-deoxy-d-mannose and 1,6-anhydro- b-d-manno-pyranose result in complete loss of activity.
    [Show full text]
  • Hexose Oxidase from Chondrus Crispus Expressed in Hansenula Polymorpha
    Chemical and Technical Assessment 63rdJECFA Hexose Oxidase from Chondrus Crispus expressed in Hansenula Polymorpha CHEMICAL AND TECHNICAL ASSESSMENT (CTA) Prepared by Jim Smith and Zofia Olempska-Beer © FAO 2004 1 Summary Hexose oxidase (HOX) is an enzyme that catalyses the oxidation of C6-sugars to their corresponding lactones. A hexose oxidase enzyme produced from a nonpathogenic and nontoxigenic genetically engineered strain of the yeast Hansenula polymorpha has been developed for use in several food applications. It is encoded by the hexose oxidase gene from the red alga Chondrus crispus that is not known to be pathogenic or toxigenic. C. crispus has a long history of use in food in Asia and is a source of carrageenan used in food as a stabilizer. As this alga is not feasible as a production organism for HOX, Danisco has inserted the HOX gene into the yeast Hansenula polymorpha. The information about this enzyme is provided in a dossier submitted to JECFA by Danisco, Inc. (Danisco, 2003). Based on the hexose oxidase cDNA from C. crispus, a synthetic gene was constructed that is more suitable for expression in yeast. The synthetic gene encodes hexose oxidase with the same amino acid sequence as that of the native C. crispus enzyme. The synthetic gene was combined with regulatory sequences, promoter and terminator derived from H. polymorpha, and inserted into the well-known plasmid pBR322. The URA3 gene from Saccharomyces cerevisiae (Baker’s yeast) and the HARS1 sequence from H. polymorpha were also inserted into the plasmid. The URA3 gene serves as a selectable marker to identify cells containing the transformation vector.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 6,713,116 B1 Aldrich Et Al
    USOO6713116B1 (12) United States Patent (10) Patent No.: US 6,713,116 B1 Aldrich et al. (45) Date of Patent: Mar. 30, 2004 (54) SWEET-STABLE ACIDIFIED BEVERAGES 4,957,763 A 9/1990 Saita et al. ................. 426/548 5,169,671. A 12/1992 Harada et al. .............. 426/658 (75) Inventors: Jessica A. Aldrich, Hazlet, NJ (US); 5,380,541 A 1/1995 Beyts et al. ................ 426/548 Lisa Y. Hanger, Basking Ridge, NJ 5.431,929 A 7/1995 Yatka et al. ................... 426/3 5,731,025 A 3/1998 Mitchell ..................... 426/548 (US); Guido Ritter, Laer (DE) 6,322,835 B1 * 11/2001 De Soete et al. ........... 426/453 (73) Assignee: Nutrinova Inc., Somerset, NJ (US) 6,372.277 B1 * 4/2002 Admiraal et al. ........... 426/548 FOREIGN PATENT DOCUMENTS (*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 W WO as: : 3.1. - - - - - - - - - - - A23L/1/236 U.S.C. 154(b) by 0 days. WO WO 98/19564 5/1998 ............. A23L/2/60 (21) Appl. No.: 09/675,825 OTHER PUBLICATIONS (22) Filed: Sep. 29, 2000 Widemann et al., “Synergistic Sweeteners”, Food Ingred. and Analysis Int., 19(6):51-52, 55-56 (abstract only), Dec. Related U.S. Application Data 1997.* (63) Continuation-in-part of application No. 09/186,275, filed on sk cited- by examiner Nov. 5, 1998, now abandoned. Primary Examiner Keith Hendricks (60) Pisional application No. 60/079,408, filed on Mar. 26, (74) Attorney, Agent, or Firm-ProPat, L.L.C. (51) Int. Cl.
    [Show full text]
  • Biochemistry Entry of Fructose and Galactose
    Paper : 04 Metabolism of carbohydrates Module : 06 Entry of Fructose and Galactose Dr. Vijaya Khader Dr. MC Varadaraj Principal Investigator Dr.S.K.Khare,Professor IIT Delhi. Paper Coordinator Dr. Ramesh Kothari,Professor UGC-CAS Department of Biosciences Saurashtra University, Rajkot-5, Gujarat-INDIA Dr. S. P. Singh, Professor Content Reviewer UGC-CAS Department of Biosciences Saurashtra University, Rajkot-5, Gujarat-INDIA Dr. Charmy Kothari, Assistant Professor Content Writer Department of Biotechnology Christ College, Affiliated to Saurashtra University, Rajkot-5, Gujarat-INDIA 1 Metabolism of Carbohydrates Biochemistry Entry of Fructose and Galactose Description of Module Subject Name Biochemistry Paper Name 04 Metabolism of Carbohydrates Module Name/Title 06 Entry of Fructose and Galactose 2 Metabolism of Carbohydrates Biochemistry Entry of Fructose and Galactose METABOLISM OF FRUCTOSE Objectives 1. To study the major pathway of fructose metabolism 2. To study specialized pathways of fructose metabolism 3. To study metabolism of galactose 4. To study disorders of galactose metabolism 3 Metabolism of Carbohydrates Biochemistry Entry of Fructose and Galactose Introduction Sucrose disaccharide contains glucose and fructose as monomers. Sucrose can be utilized as a major source of energy. Sucrose includes sugar beets, sugar cane, sorghum, maple sugar pineapple, ripe fruits and honey Corn syrup is recognized as high fructose corn syrup which gives the impression that it is very rich in fructose content but the difference between the fructose content in sucrose and high fructose corn syrup is only 5-10%. HFCS is rich in fructose because the sucrose extracted from the corn syrup is treated with the enzyme that converts some glucose in fructose which makes it more sweet.
    [Show full text]
  • Marking Scheme for the Exam
    Chemistry 2420 S10 Spring 2005 Term Exam #1 110 Minutes Name: ______________________ Student Number___________________ Marking Scheme For The Exam QUESTION # 1 2 3 4 5 6 7 8 6 12 14 14 13 39 12 9 TOTAL 119 % Question 1. (6 Marks) Under mildly acidic conditions, compound A reacts to produce compound E plus two equivalents of methanol. Identify the main functional group present in: A: ___________ E: ___________ CH3 CH3 CH 3 CH3 + NH2 H A OCH3 E + 2 CH3OH H O OCH3 2 N Provide the structures of the three additional neutral molecules (B, C and D) that are formed during the conversion. Identify the major functional group present in each of the molecules you have drawn. A E B C D Question 2. (12 Marks) Circle the structure that will best satisfy the given information. - the compound able to undergo an intramolecular cyclization to form a hemiacetal H H HO H HO OH O O O - the compound able to undergo an intramolecular cyclization to form an enamine H H H Me2N MeHN H2N O O O + - the produc t formed from treatment of 2-butanone with NaBD4 followed by a H3O work-up DO H HO D DO D HO H - the compound that would most likely be coloured O H O O - the compound capable of undergoing mutarotation O O O OH OCH3 OH CH3 H CH 3 - the compound that would not react with MeMgBr O O O OH OCH3 OH CH3 H CH3 - the compound bes t described as “anti-aromatic”: - the most stable carbocation + + + Cl Cl Cl OCH 3 H NO2 H H H Question 3.
    [Show full text]
  • Carbohydrates: Structure and Function
    CARBOHYDRATES: STRUCTURE AND FUNCTION Color index: . Very important . Extra Information. “ STOP SAYING I WISH, START SAYING I WILL” 435 Biochemistry Team *هذا العمل ﻻ يغني عن المصدر المذاكرة الرئيسي • The structure of carbohydrates of physiological significance. • The main role of carbohydrates in providing and storing of energy. • The structure and function of glycosaminoglycans. OBJECTIVES: 435 Biochemistry Team extra information that might help you 1-synovial fluid: - It is a viscous, non-Newtonian fluid found in the cavities of synovial joints. - the principal role of synovial fluid is to reduce friction between the articular cartilage of synovial joints during movement O 2- aldehyde = terminal carbonyl group (RCHO) R H 3- ketone = carbonyl group within (inside) the compound (RCOR’) 435 Biochemistry Team the most abundant organic molecules in nature (CH2O)n Carbohydrates Formula *hydrate of carbon* Function 1-provides important part of energy Diseases caused by disorders of in diet . 2-Acts as the storage form of energy carbohydrate metabolism in the body 3-structural component of cell membrane. 1-Diabetesmellitus. 2-Galactosemia. 3-Glycogen storage disease. 4-Lactoseintolerance. 435 Biochemistry Team Classification of carbohydrates monosaccharides disaccharides oligosaccharides polysaccharides simple sugar Two monosaccharides 3-10 sugar units units more than 10 sugar units Joining of 2 monosaccharides No. of carbon atoms Type of carbonyl by O-glycosidic bond: they contain group they contain - Maltose (α-1, 4)= glucose + glucose -Sucrose (α-1,2)= glucose + fructose - Lactose (β-1,4)= glucose+ galactose Homopolysaccharides Heteropolysaccharides Ketone or aldehyde Homo= same type of sugars Hetero= different types Ketose aldose of sugars branched unBranched -Example: - Contains: - Contains: Examples: aldehyde group glycosaminoglycans ketone group.
    [Show full text]
  • Structural Features
    1 Structural features As defined by the International Union of Pure and Applied Chemistry gly- cans are structures of multiple monosaccharides linked through glycosidic bonds. The terms sugar and saccharide are synonyms, depending on your preference for Arabic (“sukkar”) or Greek (“sakkēaron”). Saccharide is the root for monosaccha- rides (a single carbohydrate unit), oligosaccharides (3 to 20 units) and polysac- charides (large polymers of more than 20 units). Carbohydrates follow the basic formula (CH2O)N>2. Glycolaldehyde (CH2O)2 would be the simplest member of the family if molecules of two C-atoms were not excluded from the biochemical repertoire. Glycolaldehyde has been found in space in cosmic dust surrounding star-forming regions of the Milky Way galaxy. Glycolaldehyde is a precursor of several organic molecules. For example, reaction of glycolaldehyde with propenal, another interstellar molecule, yields ribose, a carbohydrate that is also the backbone of nucleic acids. Figure 1 – The Rho Ophiuchi star-forming region is shown in infrared light as captured by NASA’s Wide-field Infrared Explorer. Glycolaldehyde was identified in the gas surrounding the star-forming region IRAS 16293-2422, which is is the red object in the centre of the marked square. This star-forming region is 26’000 light-years away from Earth. Glycolaldehyde can react with propenal to form ribose. Image source: www.eso.org/public/images/eso1234a/ Beginning the count at three carbon atoms, glyceraldehyde and dihydroxy- acetone share the common chemical formula (CH2O)3 and represent the smallest carbohydrates. As their names imply, glyceraldehyde has an aldehyde group (at C1) and dihydoxyacetone a carbonyl group (at C2).
    [Show full text]
  • • for an Anomer, the OH Is Drawn Down. • for a Anomer, the OH Is
    How to draw a Haworth projection from an acyclic aldohexose Example: Convert D-mannose into a Haworth projection. CHO HO H HO H H OH H OH CH2OH D-mannose Step [1]: · Draw a hexagon and place the oxygen atom in the upper right corner. O O in upper right corner Step [2]: · Place the anomeric carbon on the first carbon clockwise from the oxygen. · For an anomer, the OH is drawn down. · For a anomer, the OH is drawn up. This C becomes the anomeric C. 1CHO O H O OH HO H 1 1 HO H OH H H OH anomer anomer H OH anomeric carbon - CH2OH first C clockwise from O · Always keep in mind that the anomeric carbon comes from the carbonyl carbon in the acyclic form. Step [3]: · Add the substituents of the three chiral carbons closest to the C=O. · The substituents on the right side of the Fischer projection are drawn down. · The substituents on the left are drawn up. CHO HO 2 H add H O H O H 3 C2 - C4 H HO H 4 OH OH 4 OH OH H 4 OH HO OH HO OH 3 2 3 2 H H H OH H H anomer anomer CH2OH Haworth convention - 2 Step [4]: · For D sugars the CH2OH group is drawn up. For L sugars the CH2OH group is drawn down. CHO CH2OH CH2OH HO H H O H H O H H HO H H OH OH OH OH H OH HO OH HO OH H H H OH H H anomer anomer CH2OH This OH on the right side CH OH is drawn up.
    [Show full text]
  • REFERENCE ONLY UNIVERSITY of LONDON THESIS This Thesis
    REFERENCE ONLY UNIVERSITY OF LONDON THESIS Degree Year Name of Author 0" * COPYRIGHT This is a thesis accepted for a Higher Degree of the University of London. It is an unpublished typescript and the copyright is held by the author. All persons consulting the thesis must read and abide by the Copyright Declaration below. COPYRIGHT DECLARATION I recognise that the copyright of the above-described thesis rests with the author and that no quotation from it or information derived from it may be published without the prior written consent of the author. LOANS Theses may not be lent to individuals, but the Senate House Library may lend a copy to approved libraries within the United Kingdom, for consultation solely on the premises of those libraries. Application should be made to: Inter-Library Loans, Senate House Library, Senate House, Malet Street, London WC1E 7HU. REPRODUCTION University of London theses may not be reproduced without explicit written permission from the Senate House Library. Enquiries should be addressed to the Theses Section of the Library. Regulations concerning reproduction vary according to the date of acceptance of the thesis and are listed below as guidelines. A. Before 1962. Permission granted only upon the prior written consent of the author. (The Senate House Library will provide addresses where possible). B. 1962- 1974. In many cases the author has agreed to permit copying upon completion of a Copyright Declaration. C. 1975 - 1988. Most theses may be copied upon completion of a Copyright Declaration. D. 1989 onwards. Most theses may be copied. This thesis comes within category D.
    [Show full text]
  • Hydrocolloids Structure and Properties the Building Blocks for Structure Timothy J
    Hydrocolloids Structure and Properties The building blocks for structure Timothy J. Foster 18 month Meeting, Unilever Vlaardingen, March 29‐31, 2010 Manufactured Materials Foams Emulsions Natural Materials This shows a layer of onion (Allium) cells. Targeting Hydrocolloids For Specific Applications: Approach Material Ingredient Properties Microstructure Oral Process Response Packaging Distribution Storage Process Controlled oral response Process (mouth/gut) Controlling Structure (taste, flavour, texture) CONSTRUCTION DECONSTRUCTION Designed texture/ Ingredient In body functionality Ingredient appearance/ (enzymes) behaviour Interaction with body mucins Reconstruction (associative and new phase separation) Microstructure changes as a Impact on / of starting function of enzyme action materials / structures Re-assembly of structures as a function of digestion breakdown products and body secretions (micelle formation, delivery vehicles) Single Biopolymer systems Hydrocolloid Structure/ Function Need: - define biopolymer primary structure - understand the nature of the interaction / rates - understand the solvent effects - measure material properties - test influence of primary structure variation and changes in environmental conditions on mechanical properties. Hydrocolloid Materials & Function Gelling Thickening Emulsification Pectin Pectin • Gelatin Alginate Alginate • Milk proteins Starch Starch • Egg proteins Agar LBG Carrageenan • Soya proteins Guar gum Gellan • Pea proteins Gelatin Xanthan • Gum Arabic Milk proteins Egg proteins Hydrocolloid
    [Show full text]
  • 1) Which of the Following Biomolecules Simply Refers to As “Staff of Life”? (A) Lipids (B) Proteins (C) Vitamins (D) Carbohydrates Sol: (D) Carbohydrates
    1) Which of the following Biomolecules simply refers to as “Staff of life”? (a) Lipids (b) Proteins (c) Vitamins (d) Carbohydrates Sol: (d) Carbohydrates. 2) Which of the following is the simplest form of carbohydrates? (a) Carboxyl groups (b) Aldehyde and Ketone groups (c) Alcohol and Carboxyl groups (d) Hydroxyl groups and Hydrogen groups Sol: (b) Aldehyde and Ketone groups. 3) Which of the following monosaccharides is the majority found in the human body? (a) D-type (b) L-type (c) LD-types (d) None of the above Sol: (a) D-type. 4) Which of the following is the most abundant biomolecule on the earth? (a) Lipids (b) Proteins (c) Carbohydrates (d) Nucleic acids. Sol: (c) Carbohydrates. 5) Which of the following are the major functions of Carbohydrates? (a) Storage (b) Structural framework (c) Transport Materials (d) Both Storage and structural framework Sol: (d) Both Storage and structural framework. 6) Which of the following is the general formula of Carbohydrates? (a) (C4H2O)n (b) (C6H2O)n (c) (CH2O)n (d) (C2H2O)n COOH Sol: (c) (CH2O)n. 7) Which of the following is the smallest carbohydrate – triose? (a) Ribose (b) Glucose (c) Glyceraldehyde (d) Dihydroxyacetone Sol: (c) Glyceraldehyde. 8) Which of the following is a reducing sugar? (a) Dihydroxyacetone (b) Erythrulose (c) Glucose (d) All of the above Sol: (c) Glucose. 9) Which of the following is an example of Epimers? (a) Glucose and Ribose (b) Glucose and Galactose (c) Galactose, Mannose and Glucose (d) Glucose, Ribose and Mannose Sol: (b) Glucose and Galactose 10) Which of the following has reducing properties? (a) Mucic acid (b) Glucaric acid (c) Gluconic acid (d) Glucuronic acid Sol: (d) Glucuronic acid.
    [Show full text]