Carbohydrates ppt biochemistry pharmacy for students

Carbohydrates ppt
Starch cellulose
Biochemistry

1. Carbohydrates Polyhydroxy compounds (poly-alcohols) that contain a carbonyl (C=O) group Elemental composition C x (H 2 O) y About 80% of human caloric intake >90% dry matter of plants Functional properties Sweetness Chemical reactivity Polymer functionality

2. Types of Carbohydrates

3. Monosaccharides Monosaccharides are categorized by the number of carbons (typically 3-8) and whether an aldehyde or ketone Most abundant monosaccharides are hexoses (6 carbons) Most monosaccharides are aldehydes, i.e. aldoses O H C H C OH H H C OH C O aldehyde ketone

4. Fisher projections H C OH H H H O H C 4 OH 5 6 C H 2 OH C 1 C 2 OH HO C 3 H O H C H 2 OH 1 C 2 HO C 3 H C OH 4 C OH 5 6 C H 2 OH D-fructose (an ketohexose) D-glucose (an aldohexose)

5. Cyclic Forms O OH HO OH HO H Lowest energy state H C 1 H 2 C 4 C 6 C H 2 OH C 5 H C 3 H  -D-glucopyranose (glucose) —an aldose a hexose an aldohexose — C 1 chair conformation  -D-fructopyranose (fructose) —a ketose a hexulose a ketohexose — 1 C chair conformation O C H H OH OH H OH C H 2 OH 1 2 C C 3 H C OH 4 5 6 C H

6. Ring Nomenclature pyranose is a six-membered ring (a very stable form due to optimal bond angles) furanose is a five-membered ring

7. Chirality Geometric property of a rigid object (or spatial arrangement of atoms) of being non-super-imposable on its mirror image H H C OH HO C H H C OH its mirror image is an "optical isomer" C OH C H 2 OH H C O 4 chiral center e s .g. at C2 carbon: This structure has a non- superimposable mirror image CHO (CHOH) 3 CH 2 OH H C2 OH

8. Isomers Isomers are molecules that have the same chemical   formula but different structures Stereoisomer differs in the 3-D orientation of atoms Diastereomers are isomers with > 1 chiral center. Pairs of isomers that have opposite configurations at one or   more of the chiral centers but that are not mirror images of   each other. Epimers are a special type of diastereomer. Stereoisomers with more than one chiral center which differ in chirality at only one chiral center. A chemical reaction which causes a change in chirality at one one of many chiral center is called an epimerisation.

9. Enantiomers Isomerism in which two isomers are mirror images of each other. (D vs L)

10. Anomer An anomer is one of a special pair of diastereomeric aldoses or ketoses – differ only in configuration about the carbonyl carbon (C1 for aldoses and C2 for ketoses)

11. Carbonyl Group Carbonyl groups subject to nucleophilic attack, since carbonyl carbon is electron deficient: – -OH groups on the same molecule act as nucleophile , add to carbonyl carbon to recreate ring form

12. O H H O O H O H O H O H O O 5 5 5 5 1 1 1 1  anomer  anomer Carbonyl carbon freely rotates  O can attack either side

13. Specification of Conformation, chirality and anomeric form of sugars Determination of chair conformation Locate the anomeric carbon atom and determine if numbering sequence is clockwise (n= + ve ) or counterclockwise (n= - ve ). Observe if the puckered ring oxygen atom lies “above” (p= + ve ) the plane of the ring or below (p= - ve ). Multiply n*p. If the product is + ve then C1, - ve then 1C Determination of chiral family Locate the reference carbon atom contained within the ring and determine whether the bulky substituent (OH or CH 2 OH) is equatorial (r= + ve ) or axial (r= - ve ). Multiply n*p*r. If product is + ve the chiral family is D, when it is – ve the chiral family is L

14. Determination of Anomeric form: Determine if the hydroxyl substituent on the anomeric carbon atom is equatorial (a= +ve) or axial (a= -ve). Multi[ly (n*p) by (n*p*r) by a. When the product is positive, the anomer is  ; when the product is negative the anomer is  Specification of Conformation, chirality and anomeric form of sugars

15. Mutarotation The  - and  - anomers of carbohydrates are typically stable solids. In solution, a single molecule can interchange between straight and ring form different ring sizes α and β anomeric isomers Process is dynamic equilibrium due to reversibility of reaction All isomers can potentially exist in solution energy/stability of different forms vary

16. Mutarotation : interconversion of  - and  - anomers For example, in aqueous solution, glucose exists as a mixture of 36%  - and 64%  - (>99% of the pyranose forms exist in solution).

17. Anomer Interconverision 80 70 60 50 40 30 20 10 % of all isomers D-glucose D-fructose D-mannose D-galacto s e α-pyranose β-pyranose α -furanose β-furanose Generally only a few isomers predominate

18. +57.2 o +112 o +19 o pure  -D-(+)-glucopyranose 1 [   D 66%  34%  pure  -D-(+)-glucopyranose 2 TIME (min)

19. OH HO OH O O HO OH OH O HO OH OH OH H C OH OH H OH H O OH O OH OH OH OH OH H CH 2 OH HO OH O H Mutarotation of ribose hydrate (0.09%) H H H OH CH 2 OH keto -form (0.04%)  -pyranose (20.2%)  -furanose (7.4%) HO  -pyranose (59.1%)  -furanose (13.2%)

20. Stability of Hemiacetals/Hemiketals As general rule the most stable ring conformation is that in which all or most of the bulky groups are equatorial to the axis of the ring

21. Reactions Isomerization glucose Oxidation R-CHO R-CH 2 OH f ructose mannose R-COOH R-COOH Reduction sugar sugar alcohols Acetal formation sugar glycoside Browning reactions O H C H C OH HO C H H C OH H C OH C H 2 OH carbonyl group is key

22. Isomerization Isomerization is possible because of the “acidity” of the  hydrogen O H C OH H C OH C H 2 OH  hydrogen H C H C OH (on C next to carbonyl ) HO C H O O H C C OH HO C H H C OH H C OH C H 2 OH keto form base H C C OH HO C H H C OH H C OH C H 2 OH enol form

23. Isomerization O 2 C H OH H C H C OH HO C H H C OH H C OH O 2 C H OH H HO C H H C OH H C OH H C HO C C O C H 2 OH HO C H H C OH H C OH C H 2 OH D-fructose D-glucose D-mannose

24. Oxidation/Reduction Oxidation Increase oxygen or decrease hydrogen Increase oxidation state Remove electrons Reduction Decrease oxygen or increase hydrogen Decrease oxidation state Add electrons

25. Oxidation Carbonyl group can be oxidized to form carboxylic acid Forms “-onic acid” (e.g. gluconic acid) Can not form hemiacetal Very hydrophillic Ca gluconate Can react to form intramolecular esters: lactones

26. Oxidation Also possible to oxidize alcohols to carboxylic acids “-uronic acids” Galacturonic acids Pectin Reactivity Aldehydes are more reactive than ketones In presence of base ketones will isomerize Allows ketones to oxidize

27. Reducing sugars Reducing sugars are carbohydrates that can reduce oxidizing agents Sugars which form open chain structures with free carbonyl group Reduction of metal ions – Fehling test: CuSO 4 in alkaline solution

28. Reduction Carbonyl group can be reduced to form alcohol – hydrogenation reaction Forms sugar alcohol (“-itol”) glucose mannose xylose glucitol (aka sorbitol) mannitol xylitol Sweet, same calories as sugar, non-cariogenic Very hydrophillic Good humectants

29. Stability of acetals Pyranose >>>> Furanose β -glycosidic > α-glycosidic 1,6>1,4>1,3>1,2 Allow to predict stability of glycosidic linkages in terms of their resistance to hydrolysis – Gentiobiose

30. Acid catalyzed Rxns Acid hydrolysis of hemiactals and hemiketals (mutarotation) Anhydro sugars 1C conformation Reversion sugars Formation of oligosaccharides under conditions of high sugar concentration, dilute acid……. Maple syrup, fruit juice concentrates Detection of invert sugar in juices/honey Enolization and Dehydration Formation of 3-deoxyosones and HMF/furfural

31. Hydrolysis of hemiactals and hemiketals (mutarotation) Base catalyzed loss of H from anomeric –OH Acetals and Ketals are stable Sugar esters will be hydrolyzed in alkali Enolization Favored by alkali Reduction of metal ions Alkali prevents hydrolysis of non-reducing sugar Base catalyzed Rxns

32. Introductory Biochemistry

33. What is Biochemistry? Biochemistry = chemistry of life. Biochemists use physical and chemical principles to explain biology at the molecular level. Basic principles of biochemistry are common to all living organism

34. How does biochemistry impact you? Medicine Agriculture Industrial applications Environmental applications

35. Principle Areas of Biochemistry Structure and function of biological macromolecules Metabolism – anabolic and catabolic processes. Molecular Genetics – How life is replicated. Regulation of protein synthesis

36. Once upon a time, a long long time ago….. V it a l is m : i d e a t h a t s u b st an c e s a n d p r o c e ss e s associated with living organisms did not behave according to the known laws of physics and chemistry Evidence: Only living things have a high degree of complexity Only living things extract, transform and utilize energy from their environment Only living things are capable of self assembly and self replication

37. Origins of Biochemistry: A challenge to “Vitalism.” Famous Dead Biochemist!

38. Fallacy #1: Biochemicals can only be produced by living organisms Dead Biochemist #1 1828 Friedrich Wohler

39. Fallacy #2: Complex bioconversion of chemical substances require living matter Dead Biochemists #2 1897 Eduard Buchner Glucose + Dead Yeast = Alcohol

40. Dead Biochemists #3 Emil Fischer Fallacy #2: Complex bioconversion of chemical substances require living matter

41. Fallacy #2: Complex bioconversion of chemical substances require living matter Dead Biochemists #4 1926 J.B. Sumner

42. Findings of other famous dead biochemist 1944 Avery, MacLeod and McCarty identified DNA as information molecules 1953 Watson (still alive) and Crick proposed the structure of DNA 1958 Crick proposed the central dogma of biology

43. Organization of Life elements simple organic compounds (monomers) macromolecules (polymers) supramolecular structures organelles cells tissues organisms

44. Range of the sizes of objects studies by Biochemist and Biologist 1 angstrom = 0.1 nm

45. Most abundant, essential for all organisms: C, N, O, P, S, H Less abundant, essential for all organisms : Na, Mg, K, Ca, Cl Trace levels, essential for all organism: Mn, Fe, Co, Cu, Zn Trace levels, essential for some organisms: V, Cr, Mo, B, Al, Ga, Sn, Si, As, Se, I, Elements of Life

46. Important compounds, functional groups

47. Many Important Biomolecules are Polymers p r o t e i n c o m p l e x p r o t e i n s u b u n i t a m i n o a c i d m e m b r a n e p h o s p h o l i p i d f a t t y a c i d c e ll w a ll c e llu lo s e g lu c o s e c h r o m o s o m e D N A m o n o m e r polymer supramolecular st r uc t ure l ipids pr o t ei n s c a r bo nucleic acids n u c l e o t i d e

48. L i p ids m e m b r a n e p h o s p h o l i p i d f a t t y a c i d m o n o m e r polymer supr a m o lecul a r st r uc t ure

49. Proteins m o n o m e r po l y m e r s upr a m o l e c u l a r s t ru c tu re amino acid protein subunit Enzyme complex

50. Carbohydrates c e ll w a ll c e llu lo s e g lu c o s e m o n o m e r p o l y m er s u pr a m o lecul a r s tr u c t ure

51. c h r o m a t i n D N A n u c l e o t i d e monomer po l y m e r s u p r a m o l e c ul a r s tr u c t ure Nucleic Acids

52. Common theme: Monomers form polymers through condensations Polymers are broken down through hydrolysis.

53. Prokaryote Cell

54. Cellular Organization of an E. coli Cell 200 – 300 mg protein / mL cytoplasm

55. Eukaryote Cell