This document provides information about carbohydrates: - Carbohydrates are composed of carbon, hydrogen, and oxygen and are the most abundant compounds found in nature. They are found naturally in bound form as polysaccharides, glycoproteins, glycolipids, and other complex forms. - Carbohydrates serve as sources of energy, participate in biosynthesis, and form structural tissues in plants. They also play roles in biological transport, cell recognition, and immune system modulation. - Monosaccharides can be classified based on the number of carbons and whether they are aldoses or ketoses. Disaccharides, oligosaccharides, and polysaccharides consist of multiple monosaccharide units.

1. Dr. Daxaben N. Mehta
Principal
Smt. Sadguna C.U.Shah Home Science and
C. U. Shah Arts & Commerce Mahila College,
Wadhwancity, Dist: Surendranagar
Home Science
Carbohydrates

2. Term carbohydrate is derived from the French:
hydrate de carbone
compounds composed of C, H, and O
(CH2O)n when n = 5 then C5H10O5
not all carbohydrates have this empirical
formula: deoxysugars, aminosugars
carbohydrates are the most abundant
compounds found in nature (cellulose: 100
billion tons annually)
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Carbohydrates

3. • Most carbohydrates are found naturally in
bound form rather than as simple sugars
• Polysaccharides (starch, cellulose, inulin, gums)
• Glycoproteins and proteoglycans (hormones, blood
group substances, antibodies)
• Glycolipids (cerebrosides, gangliosides)
• Glycosides
• Mucopolysaccharides (hyaluronic acid)
• Nucleic acids
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Carbohydrates

4. • sources of energy
• intermediates in the biosynthesis of other basic
biochemical entities (fats and proteins)
• associated with other entities such as glycosides,
vitamins and antibiotics)
• form structural tissues in plants and in
microorganisms (cellulose, lignin, murein)
• participate in biological transport, cell-cell
recognition, activation of growth factors,
modulation of the immune system
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Carbohydrates

5. • Monosaccharides (monoses or glycoses)
• Trioses, tetroses, pentoses, hexoses
• Oligosaccharides
• Di, tri, tetra, penta, up to 9 or 10
• Most important are the disaccharides
• Polysaccharides or glycans
• Homo and Heteropolysaccharides
• Complex carbohydrates
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Carbohydrates

6. • also known as simple sugars
• classified by 1. the number of carbons and
2. whether aldoses or ketoses
• most (99%) are straight chain compounds
• D-glyceraldehyde is the simplest of the
aldoses (aldotriose)
• all other sugars have the ending ose
(glucose, galactose, ribose, lactose, etc…)
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Carbohydrates

7. • Differences in structures of sugars are
responsible for variations in properties
• Physical Crystalline form;
solubility; rotatory power
• Chemical Reactions
oxidations, reductions, condensations
• Physiological Nutritive value
(human, bacterial); sweetness; absorption
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Carbohydrates

8. Home Science
Carbohydrates

9. H
C
(H
O
C
OH)n
CH 2 OH
Aldose
C
H
H
H
H
C
OH
C
H
C
OH
CH 2 OH
H
C
OH
Aldotriose
n=1
C
O
H
C
OH
H
C
H
C
O
O
CH 2 OH
Aldotetrose
n=2
H
C
O
H
C
OH
OH
H
C
OH
OH
H
C
OH
H
C
OH
CH 2 OH
Aldopentose
n=3
CH 2 OH
Aldohexose
n=4
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Carbohydrates

10. CH 2 OH
C
CH 2 OH
O
C
(H
C
CH 2 OH
CH 2 OH
Ketose
C
O
OH)n
CH 2 OH
CH 2 OH
H
C
OH
C
O
CH 2 OH
H
C
OH
C
O
H
C
OH
C
OH
O
CH 2 OH
Ketotriose
Ketotetrose
n=0
n=1
H
CH 2 OH
H
Ketopentose
H
OH
C
OH
n=2
CH 2 OH
Ketohexose
n=3
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Carbohydrates

11. H
H
H
H
C
O
O
H
C
OH
H
C
OH
C
O
HO
C
H
OH
C
H
H
HO
C
H
OH
C
H
C
OH
HO
C
H
CH 2 OH
C
OH
C
OH
O
HO
C
H
HO
C
H
H
C
C
CH 2 OH
H
these two aldotetroses are enantiomers.
They are stereoisomers that are mirror
images of each other
CH 2 OH
CH 2 OH
these two aldohexoses are C-4 epimers.
they differ only in the position of the
hydroxyl group on one asymmetric carbon
(carbon 4)
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Carbohydrates

12. • Pairs of stereoisomers
• Designated by D- or L- at the start of the
name.
• They are mirror images
that can’t be overlapped.
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Carbohydrates

13. Home Science
Carbohydrates

14. CH O
CHO
HO
H
H
OH
C
C
C H2 O H
C H2 O H
CHO
CHO
HO
H
C H2 O H
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H
OH
C H2 O H
Carbohydrates

15. Home Science
Carbohydrates

16. ald o tetro s es
1 CHO
1CHO
high est n u m b ered
"chira l" ca rb on
2
H
3
H
OH
OH
HO
HO
h ig h est n um b ered
"chira l" ca rb on
H
H
OH
C H 2O H
D -th reose
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high est nu m b e red
"chira l" ca rb o n
H
L -erythrose
CHO
CHO
HO
3
H
4 C H 2O H
4 CH OH
2
D -erythro se
2
H
HO
OH
H
high est n u m b ered
"chira l" ca rb on
C H 2O H
L-thre ose
Carbohydrates

17. C5, three chiral carbons,
eight stereoisomers
CHO
H
H
OH
HO
H
OH
H
OH
HO
H
OH
H
OH
H
C H 2O H
D -ribose
H
C H 2O H
D -arabinose
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CHO
CHO
CHO
OH
HO
H
H
HO
H
OH
C H 2O H
D -xylose
Carbohydrates
H
OH
C H 2O H
D -lyxose

18. 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
CH 2 OH
D-allose
CH 2 OH
CH 2 OH
CH 2 OH
D-altrose
D- glucose
D-mannose
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CH 2 OH
D-gulose
CH 2 OH
D-idose
Carbohydrates
CH 2 OH
CH 2 OH
D-galactose
D-talose

19. Home Science
Carbohydrates

20. CH 2 O H
CH 2 O H
CH 2 OH
O
CH 2 OH
hydroxyacetone
CH 2 O H
CH 2 O H
O
O
O
H
OH
H
H
OH
HO
CH 2 O H
OH
HO
H
H
H
OH
CH 2 O H
H
OH
CH 2 OH
D-ribulose
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Dxylulose
D-fructose
Carbohydrates
O
HO
H
H
OH
H
OH
H
OH
CH 2 O H
D-sedohepuloase

21. Home Science
Carbohydrates

22. • Fisher projection: straight chain
representation
• Haworth projection: simple ring in
perspective
• Conformational representation:
chair and boat configurations
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Carbohydrates

23. • draw either a six or 5-membered ring
including oxygen as one atom
• most aldohexoses are six-membered
• aldotetroses, aldopentoses,
ketohexoses are 5-membered
O
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O
Carbohydrates

24. • next number the ring clockwise starting next
to the oxygen
5
O
O
1
4
3
2
1
4
3
2
• if the substituent is to the right in the Fisher
projection, it will be drawn down in the
Haworth projection (Down-Right Rule)
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Carbohydrates

25. • for D-sugars the highest numbered
carbon (furthest from the carbonyl) is
drawn up. For L-sugars, it is drawn down
• for D-sugars, the OH group at the
anomeric position is drawn down for
and up for β. For L-sugars is up and β is
down
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Carbohydrates

26. D-glucose can cyclize in two ways forming either furanose
or pyranose structures
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Carbohydrates

27. 6
CH 2 O H
5
OH
H
1
H
HO
H
HOH 2 C
2
HO
OH
3
4
5
H
OH
H
H OH 2 C H O H H
HO
5
4
3
H OH H
2
CHO
6 CH
5
4
D-glucose
HO
OH
H
1
H
3
H
OH
3
H
6
H
H
H
OH H
HO
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O
H
OH
4
2O H
H
OH
5
OH
new chiral
center
1
OH
6
H
CH 2 OH
OH
H
6
1
2
3
H
O
H
OH H
4
CHO
6
1
2
O
4
CH 2 O H
5
O
H
OH
HO
3
H
OH
Carbohydrates
H
H
1
2
OH
OH

28. :
Glucose exists in aqueous solution primarily in
the six-membered, pyranose ring form
• Results from intramolecular nucleophilic
addition of the –OH group at C5 to the C1
carbonyl group
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Carbohydrates

29. :
• The name pyranose is derived from pyran
Pyran is the name of the unsaturated sixmembered cyclic ether
• Pyranose rings have chairlike geometry with axial
and equatorial substituents
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Carbohydrates

30. The two diastereomers are called anomers and
the hemiacetal carbon atom is referred to as
the anomeric center
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Carbohydrates

31. D-ribose and other five-carbon
saccharides can form either
furanose or pyranose structures
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Carbohydrates

32. H
5
OH
H
CHO
H
H
H
H
2
3
4
5
H
HO
H
5
2
4
3
H
5
4
O
OH
H
H
H
HO
1
H
3
OH
OH
HO
H H H
1
2
3
OH
OH
H
HO
OH
H
O
H
H
4
1
H
OH
new chiral
center
1
CHO
H
H O H OH OH
5
OH
H
OH
4
D-ribose
H
H
HO
3
HO
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H
H
H
1
H
2
O
4
HO
5
O
H
H
H
3
OH
OH
Carbohydrates
H
1
2
OH
OH

33. 1
6
C H 2O H
2
HO
H
H O H 2C
O
3
H
4
6
H O H 2C
HO
H OH
5
4
H O H 2C
1
2
3
C H 2O H
3
H
2
H
OH
H
C H 2O H
HO
4
2
C H 2O H
3
H
OH
1
OH
O
H
5
HO
4
H
C H 2O H
O
OH
H
5
O
H OH H
OH
5
6
1
6
OH
1
H
C H 2O H
2
HO
H
H
6
O
3
4
5
H
OH
H
6
H O H 2C
5
4
3
OH OH H
OH
C H 2O H
2
O
1
C H 2O H
5
H
Home Science
H
O
H
HO
2
HO
3
4
HO
6
OH
H
H OH
6
H
C H 2O H
1
Carbohydrates
4
H
5
O
H
HO
H
HO
OH
C H 2O H
3
OH
2
H
1

34. Chair and boat conformations of a pyranose sugar
2 possible chair conformations
of
Home Science -D-glucose
Carbohydrates

35. • A property exhibited by any
compound whose mirror images
are non-superimposable
• Asymmetric compounds rotate
plane polarized light
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Carbohydrates

36. Measurement of optical activity in chiral or
asymmetric molecules using plane polarized light
Molecules may be chiral because of certain atoms
or because of chiral axes or chiral planes
Measurement uses an instrument called a
polarimeter (Lippich type)
Rotation is either (+) dextrorotatory or (-)
levorotatory
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Carbohydrates

37. Home Science
Carbohydrates

38. Home Science
Carbohydrates

39. Magnitude of rotation depends upon:
Nature of the compound
Length of the tube usually expressed in decimeters
Wavelength of the light source employed
Temperature of sample
Concentration of analyte in grams per 100 ml
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Carbohydrates

40. •
•
•
•
•
•
D-glucose
D-galactose
D-mannose
D-xylose
Sucrose
Invert sugar
+52.7
+80.2
+14.2
+18.8
+66.5
-19.8
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D-fructose
L-arabinose
D-arabinose
Lactose
Maltose
Dextrin
Carbohydrates
-92.4
+104.5
-105.0
+55.4
+130.4
+195

41. • Carbonyl reactions:
• Osazone formation
• Reduction , Oxidation
• Amino Sugars
Home Science
Carbohydrates

42. • consists of reacting the
monosaccharide with phenylhydrazine
• D-fructose and D-mannose give the
same osazone as D-glucose
• seldom used for identification; we
now use HPLC or mass spectrometry
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Carbohydrates

43. The aldehyde group of an aldose react with phenylhydrazine.
O
H
CH
C NNHC 6 H 5
+ 3C 6 H 5 N HN H 2
(C HOH)n
C NNHC 6 H 5
C H 2 OH
+ C 6 H 5 N H 2 + NH 3 + H 2 O
(CHOH)n
CH 2 OH
phenylosazone
(±½ëÛ)
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Carbohydrates

44. • Aldoses may be oxidized to 3 types of acids
Aldonic acids: aldehyde group is converted
to a carboxyl group
Uronic acids: aldehyde is left intact and
primary alcohol at the other end is
oxidized to COOH
Saccharic acids (glycaric acids) – oxidation
at both ends of monosaccharide)
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Carbohydrates

45. • Br2 is a mild oxidant that gives good yields
of aldonic acid products
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Carbohydrates

46. • Aldoses are oxidized in warm, dilute HNO3
to dicarboxylic acids called aldaric acids
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Carbohydrates

47. • Enzymatic oxidation at the –CH2OH end of
aldoses yields uronic acids
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Carbohydrates

48. •
•
•
•
•
either done catalytically or enzymatically
Forms sugar alcohol (alditol)
glucose form sorbitol (glucitol)
mannose forms mannitol
fructose forms a mixture of mannitol and
sorbitol
• glyceraldehyde gives glycerol
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Carbohydrates

49. Aldoses( and ketoses) can be reduced with sodium borohydride
CH O
H O H 2C
HO
HO
H
O
HO
CH 2 O H
OH
H
HO
H
N aBH 4
HO
OH
H
H
H
OH
H
OH
OH
OH
H
OH
CH 2 O H
CH 2 O H
D -G lucitol
D -G lucose
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(D -ÆÏÌÑ ÌÇ ´¼ £©
Carbohydrates

50. Home Science
Carbohydrates

51. • These are monosaccharides which lack one
or more hydroxyl groups on the molecule
• one quite ubiquitous deoxy sugar is 2’deoxy ribose which is the sugar found in
DNA
• 6-deoxy-L-mannose (L-rhamnose) is used
as a fermentative reagent in bacteriology
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Carbohydrates

52. examples of deoxysugars
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Carbohydrates

53. Several sugar esters important
in metabolism
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Carbohydrates

54. Home Science
Carbohydrates

55. Home Science
Carbohydrates

56. • Most common are the disaccharides
• Sucrose, lactose, and maltose
• Maltose hydrolyzes to 2 molecules of Dglucose
• Lactose hydrolyzes to a molecule of glucose
and a molecule of galactose
• Sucrose hydrolyzes to a moledule of glucose
and a molecule of fructose
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Carbohydrates

57. • Malt sugar. Not common in nature except in
germinating grains.
α
(1
CH 2 OH
CH 2 OH
H
O
H
OH
4) linkage.
H
H
H
O
O
OH
H
OH
H
H
OH
H
OH
-D-glucose
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OH
H
-D-glucose
Carbohydrates

58. • Milk sugar - dimer of -D-galactose and
D-glucose. (1
4)
O
H
H
OH
O
H
O
H
OH
OH
-D-galactose
Home Science
OH
H
H
H
H
H
-
CH 2 OH
CH 2 OH
OH
or
H
OH
-D-glucose
Carbohydrates

59. CH 2 OH
• Table sugar - most
H
common sugar in all
H
OH
plants.
• Sugar cane and beet, OH
H
are up to 20% by
mass sucrose.
CH 2 OH
• Disaccharide of
H
-glucose and
H
-fructose.
(1
2) linkage
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O
H
H
OH
O
O
OH
Carbohydrates
OH
CH 2 OH
H

60. • homoglycans (starch, cellulose, glycogen,
inulin)
• heteroglycans (gums, mucopolysaccharides)
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Carbohydrates

61. • most common storage polysaccharide in
plants
• composed of 10 – 30% amylose and
70-90% amylopectin depending on the
source
• the chains are of varying length, having
molecular weights from several
thousands to half a million
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Carbohydrates

62. • Branched structure due to crosslinks.
O
H
H
OH
H
O
H
H
OH
H
H
H
O
H
H
OH
β(1
H
OH
H
CHOH H
2
OH
H
O
H
H
OH
H
OH
O
H
H
O
CHOH H
2
OH
H
O
H
H
OH
H
OH
CH
2
OH
H
H
OH
H
OH
Carbohydrates
H
H
O
O
6) link age at crosslink
Home Science
O
H
H
O
H
H
O
O
H
H
O
CHOH H
2
OH
O
H
H
OH
O
H
CHOH
2
CHOH
2
CHOH
2
CHOH
2
H
OH

63. • Main sources of starch are rice, corn,
wheat, potatoes and cassava
• Starch is used as an excipient, a binder in
medications to aid the formation of
tablets.
• Industrially it has many applications such
as adhesives, paper making, biofuel,
textiles
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Carbohydrates

64. • Energy storage of animals.
• Stored in liver and muscles as granules.
• Similar to amylopectin. α(1 6) linkage
O
O
O
O
c
O
O
O
c
O
O
O
O
O
O
O
Home Science
Carbohydrates

65. Amylose and amylopectin are the 2 forms of starch. Amylopectin
is a highly branched structure, with branches occurring every 12
to 30 residues
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Carbohydrates

66. • These materials provide a thin, viscous, jelly-like coating
to cells. The most abundant form is hyaluronic acid.
CH 2 OH
O
H
O
H
COO
H
CH 2 OH
O
H
O
H
(1
•
3)
COO
H
CH 2 OH
(1
4)
O
H
•
COO
H
O
O
HO
NH
C O
H
H
H
H
H
H
CH 3
OH
H
NH
OH
CH 3
Alternating units
of N-acetylglucosamine and
D-glucuronic acid.
CH 3
OH
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NH
C O
C O
H
H
H
H
OH
-
HO
O
H
O
O
H
H
H
OH
-
O
O
HO
H
OH
-
Carbohydrates

67. • Bacterial cell walls are composed primarily of an
unbranched polymer of alternating units of Nacetylglucosamine and N-acetylmuramic acid.
CH
2 OH
CH
O
H
H
OH
O
H
H
O
O
2 OH
H
OR
O
H
H
H
H
H
NH
C
CH
O
3
NH
C
CH
O
3
• Peptide crosslinks between the polymer strands provide
extra strength varies based on bacterium.
Home Science
Carbohydrates

68. John E McMurry : Organic Chemistry
Garrett & Grisham: Textbook of Biochemistry
Lehninger: Fundamentals of Biochemistry
Morris Hein, Scott Pattison, and Susan Arena:
Introduction to Biochemistry
Home Science
Carbohydrates

69. Home Science
Carbohydrates