1. In the name of GOD
Carbohydrate

2. Why Carbohydrates ?

3. Sugars Objectives: After studying this session you have to:
Define what a carbohydrate molecule is
Recognise and classify carbohydrate molecules
Explain why carbohydrates are important
Explain different types of isomerism in monosaccharides
Name other molecules that interact with carbohydrates and explain how and why these interactions occur
Know different names, roles, definitions, structurs and classifications of sugars, MS, OS(DS) & PS

4. Sugars/ Importance 2. The most abundant organic molecules in nature
1. Photosynthesis energy stored in carbohydrates
2. The most abundant organic molecules in nature
3. Metabolic precursors of all other biomolecules
4. Central in the metabolism of plants and animals
5. Important structural component of plants (cellulose, pectate), animals (hyaloronic acid, chitin) and bacterial cells (murein)

6. Sugars/ Importance Sugars/ Importance
6. Fuel; In animals, they represent a major part of the caloric intake.
7. Energy Storage ( glycogen, starch, inulin).
8. Cell-cell recognition
9. Adhesion (hyaluronic acid)
10. They are important in immune responses either as antigenic determinants or antibody structure
11. Protein ageing ( non-enzymatic glycation)
12. Age determinant in some protein and cells (Asialo glycoprotein)

7. Sugars/ Different names and definition
1- Carbohydrates { Cn(H2O)n }: Substances with equal ratio of carbon atom and water.
Exceptions:
*Sugars that have not the formula (deoxyribose & Fucose)
*Substances that are not sugars but have the formula { formaldehyde (C H2O) & lactic acid {C3(H2O)3}

8. Sugars/ Different names and definition
2- Glucides ( glycos= Gk. sweet) OR
Saccharides ( sakcharon= Gk. sugar)
Exceptions:
*Sugars that are not sweet (cellulose & starch)
*Sweet substances that are not sugars (glycerol, monilin, aspartam and saccharine)
3- Ose ( suffix from Fr. sugar)
4- Definition: Polyhydroxy compound with an aldehyde or a ketone group or those compounds that by hydrolysis produce such compounds.

9. Sugars Different classifications:
1- With respect to the number of building blocks they are classified into three groups:
a-Monosaccharide (mono= one) or simple sugar have just one unit.
b-Oligosaccharide (oligo= few) that are composed of Monosaccharide units
c-Polysaccharides (poly = many) are much larger sugars , containing hundreds of monosaccharide units
2- With respect being pure sugar or having other components are classified into:
a- Glycoprotein & Proteoglycane
b- glycolipid and lipopolysccharide.

10. Monosaccharides

11. Sugars/General idea The simplest sugar is Glyceraldehyde.
All other simple sugars are derived from Glyceraldehyde.
The structure of Glyceraldehyde is the basis of sugar classification into two different D or L classes.

14. Sugars/General idea They have asymmetric (chiral) carbon.
The only sugar that has not any
assymetric carbon is dihydroxyacetone.
Glucose ( dextrose) is the reference sugar in medical sciences and is the most abundant sugar that is present and used as the fuel in all living organisms.

15. MS/ Different definitions
They are called simple sugar, because by hydrolysis they can not make any other simpler sugars.
They are called Polyhydroxyaldehyde or Polyhydroxyketone.
In other words:
They are Polyhydroxy compound with an aldehyde or a ketone group.

16. Monosaccharides Different Classifications and nomenclatures:
1- On the basis of the numbers of carbon atoms: Triose, tetrose, pentose, hexose and heptose.
2- On the basis of the functional group: Aldose and ketose. In most cases the name of a ketose is make by addition of “ul” between the name of sugar and ose. Example: Ribose and ribulose, heptose and heptulose.
3-On the basis of both above properties: Aldotriose, ketotriose.

17. Monosaccharides Different properties and roles :
1- They are composed of 3-7 (3-8) carbon atoms
2-All are soluble, reducing and easily can make crystal.
3- D- family sugars are the most abundant sugars in the living organism.
4-Because of the functional groups (aldo, keto and hydroxyl groups they are reactive compounds

18. MS/ Different properties and roles
6- By becoming cyclic, 5-7 carbon sugars are called internal hemiacetal or hemiketal. In other words they are referred to those sugars that by joining of their functional group with an hydroxyl group of same molecule.
7- By combination they make oligo and polysaccharides.
8-There are different isomerisms for the MS

19. MS/ Asymmetric (chiral) carbon
Chiral means like hands.
It is referred to a carbon atom with 4 different groups linked to it.

20. Sugars/ General structure/ Cyclization
There are two different
1- methyle glucoside

21. Monosaccharides
Different isomerisms:
* Functional
* Ring
* Optic

22. MS/ isomerisms/1- Functional
* Aldose is referred to those simple sugars that have an aldehyde group as their functional group.
* Ketose is referred to those simple sugars that have an ketone group as their functional group.
Aldose to ketose conversion by enediol intermediate

23. MS/ isomerisms/Functional

24. MS/ isomerisms/ 2- Ring Pyranose is a six member ring
* By the linking of functional group to a hydroxyl group, 4-7 carbon sugars make a furan or pyran like rings. In this way, the carbon of functional group is called anomeric carbon.
Pyranose is a six member ring
sugar that may be in chair
or boat conformation.
Furanose is a five member ring
sugar that its conformation
is like a letter envelope.
Note that: Linear and cyclic sugars are isomers.

25. Sugars/ Cyclic (Ring) structure
A: Haworth projection

26. MS/ Isomerisms / Ring
Furanose/ Pyranose
Chair/ Boat

29. MS/ isomerisms/3- Optic or Steroisomerism
It is because of the presence of asymmetric carbon atom and is classified into four types:
* D & L
* Enantiomerism
* Epimerism
* Anomerism

30. D and L Monosaccharides
The —OH on the chiral atom farthest from the carbonyl group is used to assign the D or L configuration D L D

31. MS/ isomerisms/ Streoisomerism
1- Optic
a- Enantiomerism
b- Epimerism
c- Anomerism
2- Conformational
a- Chair
b- Boat

32. MS/ isomerisms/3- Optic/ 1- D & L
* D & L do not refer to the rotation of polarized light, but are stand for the family of the sugar. For showing the rotation of polarized light (+) or (- )sign are used.
* D- family sugars are abundant, natural sugars that are derived from D- glyceraldehyde so the OH group of the last asymmetric atom is at right.
* L- family sugars are rear sugars and just found in the oligosaccharides present as antigenic moieties. They can not be metabolized and make energy. The OH group of the last asymmetric atom is at left.

33. MS/ isomerisms/3- Optic/ 2- Enantiomerism ( mirror image)
* Definition:
* All OH groups have opposite orientation
* A pair of enantiomers have same name, but are shown with D or L letters .
* They rotate polarized light equally into two opposite directions, if one is D(-) the other one will be L(+).
Example: D(+) Glc & L(-) Glc or D(+)Fru & L(-) Fru

34. Specific rotation of various carbohydrates at 20oC
D-glucose +52.7
D-fructose -92.4
D-galactose
L-arabinose
D-mannose +14.2
D-arabinose
D-xylose
Lactose +55.4
Sucrose +66.5
Maltose
Invert sugar -19.8
Dextrin +195

35. MS/ isomerisms/3- Optic/ 3- Epimerism
Definition: The difference between the OH orientation of just one asymmetric carbon atom other than the last one (the one that determines the family of a sugar).
Example:
Mannose ( epimer 2 Glc)
Allose ( epimer 3 Glc)
Galactose ( epimer 4 Glc)

36. Aldoses

37. Ketoses

38. MS/ isomerisms/3- Optic/ 4- Anomerism:
Definition:
* OH orientation of anomeric carbon is the basis of this classification.
β anomer : Same orientation with the side chain
( the last carbon atom)
α anomer : opposit orientation with the side chain
Example: α or β anomer of D(+)Glc.

39. MS/ isomerisms/ optic / Mutarotaion
Mutarotaion: α or β anomer can convert to each other via an open chain intermediate. In doing so the degree of polarized light rotation changes.
At equilibrium 1/3 will be α and 2/3 will be β anomer.

40. MS/ Chiral carbon & optic isomer number
For each chiral center there are two optic isomers.
They are not superimposable.
The number of chiral carbon in:
Linear aldoses: n= N-2 so linear Glc has 24 optic isomers
Cyclic aldoses: n=N-1 so cyclic Glc has optic isomers
Linear ketoses: n= N-3 so linear Fru has optic isomers
Cyclic ketoses: n= N-2 so cyclic Fru has optic isomers

41. Isomers Aldose Ketose Conformational Configurational
Functional Isomers different atom connectivity
Steroisomers Same atom connectivity different arrangement in pace
Aldose
Ketose
Conformational
Configurational
Envelop
Boat
Chair
Ring
OPTIC
Furan
Pyran
Diasteromers are not mirror image (epimers)
Anomers
Enantiomers are mirror image

42. Too much ….. Carbohydrate will be converted into fat and stored under the skin leading to weight gain!

43. THANKS
THANKST