Post on 09-Apr-2018
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CARBOHYDRATECARBOHYDRATECHEMISTRYCHEMISTRY
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OutlineOutline
Importance of carbohydratesDefinition of a carbohydrateMonosaccharides nomenclatureStereochemistry in carbohydratesEnantiomersDrawing sugars - Fischer ProjectionsFunctions of different carbohydratesSweeteners
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Importance of CarbohydratesImportance of Carbohydrates
Primary energy store in biosphereEnergy distribution
Antigenic ABO blood groupsStructural and mechanicalcomponents of cell walls in plants
and insects, cartilage in vertebrates
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Importance of CarbohydratesImportance of Carbohydrates
Most organisms that live in air obtainenergy from the oxidation of carbohydrates
Glucose is most common simplecarbohydrate used as fuelImportant to consider structure of
carbohydratesDifferences in molecular structure areoften small but critical to their function
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W hat is a Carbohydrate?W hat is a Carbohydrate?
Aldehyde or ketone compounds with multiplehydroxyl groups (OH)
Ketones both groups attached to carbonyl group
are carbonAldehydes one carbon and one hydrogen attached
to carbonyl group
Acetone : Acetaldehyde
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W hat is a Carbohydrate?W hat is a Carbohydrate?
Simplest carbohydrate molecule is amonosaccharide : (C-H 20) n : carbonhydrate
Monosaccharides have 3 to 7 carbonsEither aldehyde or ketone group and
hydroxyl (OH) groups on nearly everycarbon
Polyhydroxyaldehydes or Polyhydroxyketones
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CARBOHYDRATESCARBOHYDRATES
Carbo hydrate s are compounds composed of carbon
andhydrates of water
Carbohydrates can also be classified as polyalcohols.
Simple carbohydrates are saccharides.
Complex sugars as starches.
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SACCHARIDESSACCHARIDESMonosaccharide One Sugar Unit
GlyceraldehydeDisaccharide Two Sugar Units
MaltosePolysaccharide More Than Two Starch
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L earning check CCL earning check CC- -11
1. W hich is a correct definition of carbohydrates?a. They are esters of alcohols and aldehydes and
ketones.b. They are polyhydric derivatives of aldehydes and
ketones.c. They are hydrates of carbon.d. They are polymers of sugars.2. Classify the following as a. monosaccharides b.
oligosaccharides c. polysaccharides
2.1 hexoses2.2 disaccharides2.3 starches2.4 celluloses
2.5 pentoses
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L earning check CCL earning check CC- -11
1. W hich is a correct definition of carbohydrates?a. They are esters of alcohols and aldehydes and
ketones.b. They are polyhydric derivatives of aldehydes and
ketones.c. They are hydrates of carbon.d. They are polymers of sugars.2. Classify the following as a. monosaccharides b.
oligosaccharides c. polysaccharides
2.1 hexoses (a)2.2 disaccharides (b)2.3 starches (c)2.4 celluloses (c)
2.5 pentoses (a)
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PolyhydroxyaldehydesPolyhydroxyaldehydes
Ribose GlucoseGalactose
R
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PolyhydroxyketonePolyhydroxyketone
R R
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Hexose: aldo & ketoHexose: aldo & keto
R R R
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MonosaccaridesMonosaccarides
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Monosaccharide NomenclatureMonosaccharide NomenclatureC Ketone Aldehyde Examples
4 Tetrose Tetrulose Erythrose,Threose
5 Pentose Pentulose Ribulose,Ribose
6 Hexose Hexulose Fructose,Glucose
7 Heptose Heptulose Sedoheptose,Sedoheptulose
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Which classification fits this sugar?
Learning check CC-2a
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Which classification fits this sugar?
DihydroxyacetoneDihydroxyacetone
Learning check CC-2a
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Which classification fits this sugar?Learning check CC-2b
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GalactoseGalactose
Which classification fits this sugar?Learning check CC-2b
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Which classification fits this sugar?
Learning check CC-2c
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GlyceraldehydeGlyceraldehyde
Which classification fits this sugar?
Learning check CC-2c
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Which classification fits this sugar?Learning check CC-2d
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DD--ThreoseThreose
Which classification fits this sugar?
Learning check CC-2d
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Which classification fits this sugar?
Learning check CC-2e
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Ketoheptose
SedoheptuloseSedoheptulose
Which classification fits this sugar?
Learning check CC-2e
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Chiral MoleculesChiral Molecules
Mirror images
but notsuperimposable,
L ike your hands
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Are these compounds the same?Are these compounds the same?
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Nonsuperimposable mirror imagesNonsuperimposable mirror images
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Different CompoundsDifferent Compounds
Nonsuperimposable so different compoundsOne carbon atom is chiral (not symmetric)Nonsuperimposable mirror images are calledenantiomers
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EnantiomersEnantiomersStereoisomers are
molecules that have thesame bonds connectingthe same atoms butdifferent relativeorientations of thebonds
Enantiomer : one type of stereoisomer
Nonsuperimposablemirror images
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Enantiomers are different compoundsEnantiomers are different compounds
Different relative orientations of bonds in a pair of enantiomers
cannot be changed by rotationabout the bondsOnly be changed by breaking
bonds and remaking themOne enantiomer can only be
changed into another enantiomer by chemical reaction
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Stereoisomers: important implicationsStereoisomers: important implicationsStarch and cellulose both polymers of
glucose units linked together C4 of one glucose bonded to C1 of next
glucoseOnly difference is the direction of the
bond
Cellulose bond points up, in starchbond points downHumans can digest starch but not
cellulose
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Chiral Carbon AtomChiral Carbon Atom
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C
C
CH
H OH
OH
OH
beam of x-rays
crystal of (+)-glyceraldehyde
XX--RAY DIFFRACTIONRAY DIFFRACTIONSCATTERING PATTERN - EXPOSED FILM
calculation
CC
CH
H OH
OH
OH
structure( = D )
Structures can be determinedby mathematical analysis of the scattering pattern.
Method developed by Max von Laue (1912)
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RELATIVE CONFIGURATIONRELATIVE CONFIGURATION
D- , L-
Configuration is related to eitherD-glyceraldehyde or L-glyceraldehyde,
from which it may be synthesized.
ABSOLUTE CONFIGURATIONABSOLUTE CONFIGURATION
R- , S-The actual configuration about astereocenter - just as it really is inthree-dimensional space. Uses theSequence Rule to specify R or S.
SPECIFIC ROTATIONSPECIFIC ROTATION(+)- , (-)-
d- , l-
Specifies whether the compound isDextrorotatory or Leveorotatory whenplaced in a polarimeter.
older terms, not much used today
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There is no implied relationship among the terms!
R,S +, -
D,L
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Glyceraldehyde EnantiomersGlyceraldehyde Enantiomers
Groups attached to an asymmetric carbon atom takeeither of 2 fixed positions with respect to other carbon atoms
-OH group can extend either right or left of the carbonchain with reference to the CHO and CH 2OHgroups
RRLL
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Glyceraldehyde EnantiomersGlyceraldehyde Enantiomers
Orient molecule so carbonylis at top
If hydroxyl (OH) on highestnumbered chiral carbon
to the right D-glyceraldehyde
to the left L -glyceraldehyde
Dexter = right in latinL aevus = left in latin
RRLL
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Fischer ProjectionsFischer ProjectionsDrawing 2D images representing 3D configuration
of molecule is difficult but possible by using setof rules
Acyclic compounds drawn so that vertical bondsrepresent bonds pointing back and horizontal
bonds are bonds pointing forward
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Fischer ProjectionsFischer Projections
H O
C
C
CH 2OH
HO H
H OC
C
CH 2OH
H OH
Glyceraldehyde
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DRA W ING FISHER PROJECTIONSDRA W ING FISHER PROJECTIONS
When drawing Fisher projections for saccharides, thealdehyde carbon is alwaysdrawn up.This will then be the #1 carbon.
Fisher structures can also berepresented as stick drawingsas illustrated in the next slide.
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Stick RepresentationsStick Representations
H O
C
C
CH 2OH
HO H
H OC
C
CH 2OH
H OH
HO H
C
OH
C
H OH
C
OH
CH 2OH
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Fischer ProjectionsFischer Projections
galactosegalactose
GlucoseGalactose
CC CC CC CC CC
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Fischer ProjectionsFischer Projections
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Fischer ProjectionsFischer Projections
DD--riboseribose
CC
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Fischer ProjectionsFischer Projections
DD--glyceraldehydeglyceraldehyde
CC
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SACCHARIDE STRUCTURESACCHARIDE STRUCTURE
From the Fisher projection of glyceraldehyde we see that:
The end group is an aldehyde. The end group carbon (the
aldehyde carbon) is always the
#1 carbon. The #2 carbon has an alcohol
group.
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SACCHARIDE STRUCTURESACCHARIDE STRUCTURE
Sacharides undergo End GroupConversion.The Aldehyde end group convertsto an Alcohol group,The #2 carbon converts to aKetone.Notice the hydrogen moves and thebonds change.
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End Group ConversionEnd Group Conversion Aldehyde carbon is always number one carbon. Aldehyde carbon is always number one carbon.
H O
C
C
C
CH 2OH
H OH
H OH
H O
HOH
Note alcoholgroup
Note formation
of Ketone
ErythoseErythulose
H OH
C
C
C
CH 2OH
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End group conversionEnd group conversion
Biochemically is
L OBRY DE BRUYN TRANSFORMATION
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Naming SaccharidesNaming Saccharides
Saccharides are also known assugars.The functional group name for sugars
is ose.Prefix will be our usual designation of number of carbons (1c= meth, 2C=eth, , 10C = dec, etc.)The end group name can also beused to catagorize sugars asaldehydes (aldose) or ketones(ketose).
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NamingNaming common and as osecommon and as ose
H OH
C
OH
CH 2OH
H
OH
C
OH
CH 2OH
OH
H
H OH
C
OH
CH 2OH
H
H
OH
OH
HOH
C
OHH
CH 2OH
H
H
OH
OH
H O
glyceraldehydetriosealdotriose
therosetetrosealdotetrose
ribosePe n tosealdope n tose
fructosehexoseketohexose
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IsomersIsomersIsomers Organic molecules with
the same molecular formula butdiffer in structure or arrangement of atoms.
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StereoisomersStereoisomers
Stereoisomers:Same molecular formula but
different atomic arrangement inspace.
Examples:C 3H6O
CH 2OHCH 2OHCH(=O) CH 2OHCH(=O)CH 2OH
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L earning check CCL earning check CC- -33
Classify the following pairs as:A. Enantiomers B. stereoisomers
1. And
2. and
HO H
H OHC
OH
CH 2OHH O
CH
CH2OH
OH
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L earning check CCL earning check CC- -33
Classify the following pairs as:A. Enantiomers B. stereoisomers
1. And ENANTIOMER
2. and ISOMER,functional
HO H
H OHC
OH
CH 2OHH O
CH
CH2OH
OH
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Fisher StereoisomersFisher Stereoisomers
CHO
H
OH
HH
CH 2OH
HOHO
H
HO
CHO
H
OH
HOH
CH 2OH
HHO
H
HO
L-glucose D-glucose
1
2
3
4
5
6
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DD--glucoseglucoseCommon names:
glucosedextrose
Natural Source:Fruits, vegetables, cornsyrup and honey
Importance:Building block for disaccharides (such assucrose, lactose andmaltose) andpolysaccharides (starch,cellulose and glycogen)
CHO
H
HO
HH
CH 2OH
OHOH
H
OH
1
2
3
4
5
6
Diseases:Hypoglycemia/Hyperglycemia
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DD--galactosegalactoseNatural Source:
None for free formFormed by hydrolysis of milkmaltose
Importance:
Cellular membranes of brain &nervous system.
Dificiency diseases:Galactosemia:
Enzyme to digest galactosemissing and levels build in bloodcause mental retardation, cataractsand cirrhosis.
CHO
H
HO
HO
HCH 2OH
OHH
H
OH
1
2
3
4
5
6
ff
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DD--fructosefructose
Common names:L evulose and fruitsugar
Natural Source:Fruit juice and honeyHydrolysis of sugar
Importance:Due to sweetness,used as sugar
CH OH
H
HO
HO
HCH 2OH
OHH
H
O
1
2
3
4
5
6
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MutarotationMutarotation
Sugars can exist as linear structures.
Mostly they exist as cyclicstructures.
The linear form mutates into thecyclic form.
This conversion can be drawn asa Haworth structure.
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Haworth StructuresHaworth Structures Step 1Step 1
CHO
H
HOHH
CH 2OH
OHOHH
OH
1
2
3
4
5
6 CHOHOHHH
HOH 2C
OH OH H OH
123456
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Haworth StructuresHaworth Structures Step 2Step 2
CHOHOHHH
HOH 2C
OH OH H OH
123456
CHOH
OH
H H
HOH 2C
OH
OH
H OH
1
23
4
5
6
H h SH h S S 3S 3
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Haworth StructuresHaworth Structures Step 3Step 3
CHOHOH
HH
HOH 2COH
OH
H OH
1
23
4
5
6
CHOHH
OH
H H
HOH 2CO
OH
H OH
1
23
4
5
6
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AnomersStereoisomers formed when ring is formed ( E , F).
CO
CH 2OH
OHCH
HO
H
HC
OH
OH
CH
HO
HO HC
OH
C H
H C OH
C H
H
HO
H C
CH 2OH
O
C C
O
CH 2OH
CH
HO
H
HC
OHCH
HC
OH
or
E is same side with ring
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Six a nd Fiv e M ember Ri ngsSix a nd Fiv e M ember Ri ngs
Py ranFuran
o o
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Fisher & Harworth Projection Forms
OH
OH
CH
H C OH
C H
H
HO
H C
CH 2OH
O
C
OH
O
OH
OHHO
CH2
OH
1
23
45
6
E - D - Gl ucop yranose
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EE-- and and F F-- Gluc oseGluc ose
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EE--Gluc oseGluc ose F F--Gluc oseGluc ose
H H
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O
OH
OH
OH
OH
CH2OH
H
H
H
HH
O
H
H
H
H
H
OH
OH
OH
OHCH2OH
C
H
C OHH
CHO H
C OHH
CH
CH2OH
O
OHC
H
CHO H
C OHH
CHO H
C H
CH2OH
O
HO
E -D- glucose E- L- glucose
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1 . Gl ucose
OH
OH
CH
H C OH
C H
H
HO
H C
CH 2OH
O
C
OH
O
OH
OHHO
CH2 OH
1
23
4
5
6
E-D-Gl ucop yranose
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HOC
O
CH 2 OH
CH
HO
H
HC
OHCH
H C
OH
HO
OH
CH
H C
OH
C H
H
HO
H C
CH 2 OH
O
C
C
O
CH 2 OH
CH
HO
H
HC
OH
CH
H C
OH
OH
CO
CH 2 OH
OHCH
HO
H
HC
OHCH
OHH C
OH
OH
CH
H C OH
C H
H
HO
H C
CH 2 OH
O
C
-D-Glucofuranose(0.5%)EE -D-Glucopyranose(35%)
-D-Glucofuranose
(0.5%)
F F -D-Glucopyranose (65%)
Aldehydo-D-glucose (0.03%)
Fisher Projection Form
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2. G alactose
Component of lactose
E-D-G alactop yranose
O
OH
OH
CH2 OH
HO
OH
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3 . Fructose
D- Fructose F-D- Fructose E -D- Fructose
CH 2OH
O
CH 2OH
C
HO HC
OHCH
H C
OH
O
CH 2OH
C
HO HC
OHCH
H C
CH 2OHCH 2OH
CH
HO
H C OH
C HHO
C
OH
CH 2OH
O
or
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L earning check CCL earning check CC- -44W rite the HA W ORTH Structures of the following
monosaccharides:
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L earning check CCL earning check CC- -44W rite the HA W ORTH Structures of the following
monosaccharides:
Glucose glucopyranose
OH
OH
CH
H C OH
C H
H
HO
H C
CH 2OH
O
C
OH
O
OH
OHHO
CH2 OH
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L earning check CCL earning check CC- -44W rite the HA W ORTH Structures of the following
monosaccharides:
fructose fructopyranose
HOCH CH 2OH
OH HO
H OHHO H
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L i h k CCL i h k CC 44
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L earning check CCL earning check CC- -44W rite the HA W ORTH Structures of the following
monosaccharides:
mannose mannopyranose
O
CH2 OH
OH
OH
OH
HO
L i h k CCL i h k CC 44
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L earning check CCL earning check CC- -44W rite the HA W ORTH Structures of the following
monosaccharides:
gulose gulopyranose
O
CH2 OH
HO
OH
OHOH
DisaccharidesDisaccharides
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DisaccharidesDisaccharidesformed by dehydrationformed by dehydration
HOH
H H
HOH 2C O
OH
H OH
1
23
4
5
6
HH
HOH 2CO
OH
H OH
1
2
34
5
6
H
OH
OH
-, D-glucose
, D-fructoseCH 2OH
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SucroseSucrose
HOH
H H
HOH 2C O
OH
H OH
1
23
4
5
6
HH
HOH 2CO
OH
H OH
1
2
34
5
6
H + HOH
O
, -1,2 glycosidic bond
Weve seen the ether
link
CH 2OH
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1 ,2-E-D-Gl ucop yranos yl F-D- Fructofuranoside
O
OH
OHHO
CH2 OH
CH 2OH
OCH 2OH
O
HO
OH
H1
23 4
5
6
Invert sugar is the h ydro lyzed sucrose into g lucose and fructose.
Sucrose
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O
OH
OHHO
CH2 OHO
OH
OH
CH2 OH
O
OH
1 ,4- F-D-Gl ucop yranos yl - F-D-Gl ucop yranose
Ce ll obiose
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L actoseP
r inc
ipal s
uga r in m i
lk
O
OH
OH
CH2 OHO
OH
OH
CH2 OH
O
OH
OH
1,4 - F-D-G a la ct opy r anos y l- E-D- Gluc opy r anose
1,4 - F-D-G a la ct opy r anos y l- F-D-Gluc opy r anose
ff
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1,6
-E
-D-Ga
lactop yranos y
l- 1,2
-E
-D-Glucop yranos y
l - F
-D-
Fructofuranoside
2
2
2
2
elb iose ucrose oiet y
R affinose
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1 ,6-E-D-G alactop yranos yl- 1 ,6-E-D-G alactop yranos yl 1 ,2-E-D-Gl ucop yranos yl- F-D- Fructofuranoside
F latu lence Factor
2
2
2
2
2
Stach yose
PolysaccharidesPolysaccharides
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yy
C ll l
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Polymer of F-D-Gl ucose ( 1 , 4) linkage.
R epeating ce ll obiose moiet y.
O
OH
OH
CH2 OH
OH
O OO
O
OH
OH
CH 2 OH
O
OH
OH
CH 2 OH
O
OH
OH
CH 2 OH
O
OH
OH
CH2 OH
O
OH
OH
CH 2 OH
O
OH
OH
CH 2 OH
O
OH
OH
CH 2 OH
n
Ce ll ulose
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PolysaccharidesPolysaccharides
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PolysaccharidesPolysaccharides
Starch
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T he reserve carboh ydrate of p lants. Occurs as granu les in the ce ll .
Made of am ylose and am ylopectin.
Am ylose --- Polymer of E-D- Gl ucose ( 1 " 4) linkage -straight -chain.
Starch
O
OH
OH
CH2OH
OHO OO
O
OH
OH
CH2OH
O
OH
OH
CH2OH
O
OH
OH
CH2OH
O
OH
OH
CH2OH
O
OH
OH
CH2OH
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Am y lose
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Am y lopectin
Polymer of E -D-Gl ucose ( 1 -> 4) linkage in addition to
E -D-Gl ucose ( 1 " 6) linkage.
T he length of linear units in am ylopectin is on ly 25.
E - (1 " 4) linkage (25) to E - (1 " 6) l inkage.
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Am ylose and Am ylopect inAm ylose and Am ylopect in
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Gl ycogen
Anima l starch.
E - (1 " 4) l inkage and E - (1 -> 6) l inkage
1 2 : 1
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Gl yc ogen
i
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Polymer of 1 ,4-E -D-G alacturonic acid ( 1 , 4) &Meth ylga lacturonate
Pectin
O
OH
OH
OH
OO
O
O
OH
OH
O
OH
OH
O
OH
OH
O
OH
OH
O
OH
OH
COOH COOCH 3 COOCH 3 COOH
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L earning check CCL earning check CC- -55
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L earning check CCL earning check CC 55
Give the monosaccharide components of the followingoligosaccharides and polysaccharides:1. Maltose (glucose)2. L actose (glucose, galactose)
3. Cellulose (glucose)4. Sucrose (glucose, fructose)5. Stachyose (glucose, galactose, fructose)6. Raffinose (glucose, galactose, fructose)
7. Glycogen (glucose)8. Starch (glucose)9. Cellobiose (glucose)10. Amylose (glucose)
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Functions of Polysaccharides
1 . Viscosit y contro l
2. T exture contro l
3 . Emu lsif ying agent
4. Water - binding capacit y
5. Stabi l izer
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D et erm ina t ion
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1. M onos acch
a r ides and Oligos a
cchar ides
A . E nz ym a t ic M eth od
1. Gluc ose oxidase
2. H exok inaseB . C h rom a t ogr ap h y M eth od
1. T h in lay er ch rom a t ogr ap h y
2. G
as ch
rom atogr ap
hy
3. L iq u id c olu mn ch rom a t ogr ap h y
2. P olysa cch ar ides
D et erm ina t ion
Gl O id S t
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Gl ucose Oxidase S ystem
D-Gluc ose + O 2 Gluc on ic Ac id + H 2O 2
H 2O 2+ 0 - D ia n isid ine 2 H 2O + Oxi d ized 0-D ia n isid ine(C olor less) (Brown )
OCH3
H3CO
H2 N NH2
H3CO OC3
HN N
Gl ucose Oxidasse
Peroxidase
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PolysaccharidesQ uantification depends on chemical or enzymatichydrolyses of them into monomers and analysis of themonomers.
Q ualitative Analyses
1. Amylose + I - Blue color
Use spectrometer for determining the amylose - iodine
blue color
2. Amylopectin + I - Reddish color .
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R elative Sweetnes of Sugars
Sucrose 1 00
Gl ucose 74
Fructose 1 74
L actose 1 6
Invert Sugar 1 26Ma ltose 3 2
G alactose 3 2
W hy is sugar sweet?W hy is sugar sweet?
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Molecules, including non-sugars, taste sweetbecause they bind to sweet receptors on thetongue
W hy is sugar sweet?W hy is sugar sweet?
T ab le 3 .6
Types Of SweetenersTypes Of Sweeteners
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ypyp
Caloric SweetenersSugars
Sugar AlcoholNon-CaloricSweeteners
SugarsSugars
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gg
Includes Many Caloric SweetenersRefined Sugars L actoseCorn Sweeteners GlucoseInvert Sugars DextroseMaltose Honey
HFCS SyrupsConcentrated Fruit Juices
Health Effects of SugarsHealth Effects of Sugars
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gg
Nutritional DeficienciesSugar Can Only Contribute To
Deficiencies By Displacing
NutrientsSugars Are Not Bad But NutrientDense Foods Must Come First
Amount Of Sugar Depends OnCalories Available Beyond ThoseNeeded For Nutrients
Health Effects of SugarsHealth Effects of Sugars
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gg
Tooth DecaySugars And Starches Contribute To
Decay
Bacteria In Mouth Ferment Sugars AndProduce Acid That Dissolves EnamelSugar Only One Of Many Factors
HowL
ong Food On TeethHow Often Food EatenDental Hygiene
Health Effects of SugarsHealth Effects of Sugars
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Diabetes/HypoglycemiaGlucose May Be Modified As Part Of
Treatment
Hormonal Regulation Or Obesity (InCase Of Type 2 Diabetes) NotGlucose
Sugars Do Not Cause A Greater Glycemic Index Than ComplexCarbohydrates
Health Effects of SugarsHealth Effects of Sugars
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gg
Hyperactivity/Misbehavior In Children Controlled Studies Failed To Show
An Adverse Relationship Between
Sugar And Hyperactivity Or Misbehavior In Children Carbohydrates, Including Sugars,
Stimulate Production Of Serotonin,Makes A Person Sleepy AndSluggish
Health Effects of SugarsHealth Effects of Sugars
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gg
Heart DiseaseNormal Sugar Intakes do not Raise
Triglycerides, If Calories In Balance
Very H igh Intakes Of Sucrose AndFructose Can Increase TriglyceridesGlucose Causes Insulin Release
Some People Over Produce Insulin InResponse To High Glucose Or Carbohydrate
Health Effects of SugarsHealth Effects of Sugars
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gg
ObesityObesity Due To Energy ImbalanceNo Direct Connection Between Sugar
And Obesity, Unless Excess Sugar Containing Foods L eads To EnergyImbalance
Foods High In Sugar Often High In Fat
Increase In Calorie Intake Has ComeFrom Carbohydrates, And PrimarilySoft Drinks
Sugar AlcoholsSugar Alcohols
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gg
Provide Calories, But Fewer ThanSugars Because Not CompletelyAbsorbed
ProductsW
ith Sugar Alcohols Can BeL abeled Sugar Free or Reduced Calorie
Incomplete Absorption Can CauseGas, Abdominal Discomfort andDiarrhea
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Accepted Daily Intake (ADI)Accepted Daily Intake (ADI)
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Amount/Kg Body W eight PersonCan Safely Consume EverydayOver A L ifetime W ithout Risk
Conservative L evel Usually 100Times L ess Than Maximum L evel
AtW
hich No Observed Effects
NonNon--Caloric SweetenersCaloric Sweeteners
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FDA Petitioned Non-CaloricSweeteners
CyclamateAlitameNeotame
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Saccharine SafetySaccharine Safety
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Used Over 100 Years In USNot Metabolized By Body, Rapidly
Excreted, Does Not Accumulate In
BodyOriginally on GRAS L istSafety Q uestions Arose In 1977Rat Study Suggested L arge Doses
Increased Risk Of Bladder Cancer
Saccharine SafetySaccharine Safety
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FDA Proposed Ban On SaccharineCongress Imposed Moratorium On
Ban, Until 1991 W hen BanW
ithdrawnL arge Human Studies Do Not SupportAn Association Between SaccharineAnd Cancer For Population As AW hole
Subgroup May Have Increased Risk
Aspartame SafetyAspartame Safety
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Composed Of:PhenylalanineAspartic AcidMethyl Group
Extensive Studies Document
Safety, Except For People W ithPKU
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DiketopiperzineDiketopiperzine
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In L iquid Systems AspartameBreaks Down To Diketopiperzine(DKP) W ith Heat Exposure And
L oses Sweetness.Studies Have Shown DKP is Not A
Concern, If All Aspartame
Converted To DKP,Below The ADI Of 3,000 mg/kg
Methyl GroupMethyl Group
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During Metabolism:Methyl GroupMethanol
FormaldehydeCarbon Dioxide
Amount Produced Fall Below L evels
That W ould Cause HarmMany Juices Produce More Methanol
Than Aspartame In A Diet Soda
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Other AccusationsOther Accusations
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Some People Claim They HaveUnusual Sensitivity To Aspartame
Headaches
DizzinessMood AlterationsFatigue
Double Blind Studies Have Failed ToReproduce Reactions
CyclamateCyclamate
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Approved By FDA In 1949, Banned In1969 Based On A Study IndicatingCaused Bladder Cancer In Rats
Has Concluded Cyclamate Or By-Products Do Not Cause Cancer
However, May Promote Cancer Once
Started,More Research Needed
Special PopulationsSpecial Populations
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ChildrenHighest Intake Of Non-Caloric
Sweeteners Due To High Food/FluidIntake For Size
Suggested Children L imit SaccharinIntake
Current Aspartame And Acesulfame KIntakes For Children Below ADI
Special PopulationsSpecial Populations
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Pregnant W omenConsider Careful Use Of SaccharinAspartame W ithin FDA Guidelines
Appears SafeFetal Phenylalanine L evels ExceedMaternal L evels, But Below L evels ThatW ould Cause Neurological Problems InFetus
Acesulfame K Determined Safe
Chemical Tests for carbohydratesChemical Tests for carbohydrates
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1. Molisch Test2. Iodine Test3. Barfoeds Test4. Seliwanoffs Test5. Fehlings Test6. Benedicts Test7. Nylanders Test
8. Bial-Orcinol Test9. Mucic Acid Test10.Osazone Test
Chemical Reactions of Chemical Reactions of carbohydratescarbohydrates: :
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carbohydratescarbohydrates: :
1.Ester formation2.Reduction
3.Oxidation4.Hydrolysis -
a. with acidsb. with enzymes
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END OF THE L ECTUREEND OF THE L ECTURE