Upload
putri-laksono-indah-budiasih
View
229
Download
0
Embed Size (px)
Citation preview
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 1/32
Polysaccharides
• Polysaccharides are chains of five or more monosaccharide: – Starch – glucose polymer that is the plant storage carbohydrate
– Glycogen – glucose polymer that is the animal storage carbohydrate
– Cellulose – glucose polymer that is a major component of the cellwall in plants & algae.
– Agar – natural component of certain seaweed polymer of galactose & sulfur containing carbohydrates.
– Chitin – polymer of glucosamine (an amino sugar), foundin the exoskeleton of bugs.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 2/32
Starch
• Starch is used for energy storage in plants
• Two types: amylose and amylopectin. On completehydrolysis each type gives only D-glucose
• Amylose: is composed of continuous, unbranchedchains of up to 4000 D-glucose units joined bya-1,4-glycoside bonds
• Amylopectin: is a highly branched polymer of D-glucose. Chains consist of 24-30 units of D-glucose joined by a-1,4-glycoside bonds andbranches created by a-1,6-glycoside bonds
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 3/32
Amylose• Soluble starch, polymer of D-glucose.
• Starch-iodide complex, deep blue.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 4/32
Amylopectin
Branched, insoluble fraction of starch.
A-1,4-glycosidic linkage
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 5/32
Glycogen
• Glucose polymer, similar to amylopectin, buteven more highly branched.
•Energy storage in muscle tissue and liver.
•The many branched ends provide a quick means of
putting glucose into the blood.
• A nonlinear polymer of D-glucose units joined
by a-1,4- and a-1,6-glycoside bonds bonds.
The total amount of glycogen in the body of a well-
nourished adult is about 350 g (about 3/4 of a pound)divided almost equally between liver and muscle.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 6/32
Cellulose• Polymer of D-glucose, found in plants.
• Mammals lack the -glycosidase enzyme.Average molecular weight of 400,000,corresponds to
approximately 2800 D-glucose units per molecule.
OCH2OH
HOOH
O
OOCH2OH
HOOH
O
O HO
CH2OH
OH
O
-glucosidic linkage
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 7/32
Chitin• Polymer of N -acetylglucosamine.
•Exoskeleton of insects.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 8/32
Polysaccharides Digestion
Glucose Polymers
Starch is digestable
Cellulose is not
digestable by humans
Why?
It’s
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 9/32
Modification of Cellulose
• Cellulose Nitrate guncotton
•
Pyroxylin Partially nitrated photographic film
•Cellulose Acetate film
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 10/32
Cellulose fibre - Rayon
Cellulose OH Cellulose O-Na+NaOH
Cellulose OCS-Na+
S
S C S
Sodium salt of a xanthate ester
H+
spinneret Cellulose OH
Cellulose fibre
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 11/32
Biological Sugars and reactions
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 12/32
Membrane Carbohydrates• Membranes of animal plasma cells have large
numbers of bound small carbohydrates to them.
•these membrane-bound carbohydrates are part of
the mechanism by which cell types recognize eachother; they act as antigenic determinants
•
among the first discovered of these antigenicdeterminants are the blood group substances
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 13/32
ABO Blood Classification
NAGal Gal NAGluCell membrane
of erythrocyte
-1,4-) -1,3-) -1-)
Fuc
-1,2-)
NAGal = N-acetyl-D-galactosamineGal = D-galactose
NAGlu = N-acetyl-D-glucosamine
Fuc = L-fucose
missing in
type O blood
D-galactose intype B blood
•In the ABO system, individuals are classified
according to four blood types dependent upon whichsugars are present on the surface
• A, B, AB, and O
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 14/32
‘Chemstrip Kit’
Blood glucose test for diabetics
Based on reaction of o-toluidine with glucose
CHO
OHH
HO H
OHH
OHH
CH2OH
H2N
H3C
CH
OHH
HO H
OHH
OHH
CH2OH
N
H3C
Gl A
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 15/32
Glucose Assay
• The o-toluidine test is applied directly to serum,plasma, cerebrospinal fluid, and urine
•Diabetes: A common analytical procedure in the
clinical chemistry laboratory is the determination
of glucose in blood, urine, or other biological fluid
• glucose reacts with 2-methylaniline (o -toluidine) in thepresence of acetic acid to give an imine which has ablue-green color
– the intensity of the absorption at 625 nm is proportional tothe glucose concentration
• Galactose, mannose, and to a lesser extent lactose andxylose also react with o-toluidine to give colored iminesand, therefore, have the potential for false positive.
samples as small as 20 L (microliters) can be used.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 16/32
Glucose Assay• The glucose oxidase method is completely
specific for D-glucose
+
+
glucoseoxidase
D-Gluconic acid
Hydrogen
peroxide
- D-Glucopyranose
OHOH
HO
HOCH2 OH
O
H2 O2
O2
+ H2
O
CO2 H
CH2 OH
OHH
HHO
OHH
OHH
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 17/32
Glucose Assay
• O2 is reduced to hydrogen peroxide H2O2
• the concentration of H2O2 is proportional to the
concentration of glucose in the sample
• in one procedure, hydrogen peroxide is used to oxidize
o-toluidine to a colored product, whose concentrationis determined spectrophotometrically
peroxidase+colored product+o-toluidine H2 O2
H2 O
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 18/32
Vitamin C - A monosaccharide?• Vitamin C, vital for life is a necessary part of our
diet because we cannot synthesize it. (Mostplants and animals except primates and guineapigs can make their own Vitamin C).
•It is needed to maintain health of dentine, cartilage,connective tissue and bone.
•Recommended daily allowance ~45mg for adults
(60mg if pregnant, 80mg if lactating).
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 19/32
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 20/32
Glycocalyx
The outer viscous covering of fibersextending from a bacterium
composition: The glycocalyx is usually a viscous
polysaccharide and polypeptide slime.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 21/32
Glycocalyx of
IntestinalEpithelium
Note that some
carbohydrates are
covalently attached tomembrane
components, while
others are secreted as
extracellular matrix
Fig 16, The Cell, D.W.Fawcett (1981)
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 22/32
Glycocalyx of Lymphocyte
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 23/32
Diagram of Glycocalyx
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 24/32
Ribonucleosides
A -D-ribofuranoside bonded to a heterocyclicbase at the anomeric carbon.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 25/32
Ribonucleotides
Add phosphate at 5’ carbon.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 26/32
Nucleic Acids
• Polymer of ribofuranoside ringslinked by phosphate esters.
•Each ribose is bonded to a base.
•Ribonucleic acid (RNA)
•Deoxyribonucleic acid (DNA)
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 27/32
Structure of RNA
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 28/32
Structure of DNA
• -D-2-deoxyribofuranose is the sugar.
•Heterocyclic bases are cytosine, thymine(instead of uracil), adenine, and guanine.
Linked by phosphate ester groups to formthe primary structure.
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 29/32
Base Pairings
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 30/32
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 31/32
DNA Replication
7/31/2019 Polysaccharide Learning Material
http://slidepdf.com/reader/full/polysaccharide-learning-material 32/32
Other Nucleotides
• Adenosine monophosphate (AMP), aregulatory hormone.
• Nicotinamide adenine dinucleotide
(NAD), a coenzyme.
• Adenosine triphosphate (ATP), an energy source.