polysaccharides

1.  Polymer of D- fructose , linked by ß- (1-2)
glycosidic linkage.
 Levorotatory, MW. 5000
 Occur in the tubers of some plants.
 Is not utilized as food.
 Importance:-
 Role in the glomerular filtration rates.
 estimation of body water volume.

2. Bacterial and yeast Polysaccharides.
• (α -1-6) linked poly-D-glucose.
• Branched with (α -1-3) ,(1-4),MW 1-million
to 4-million.
• Some sticky dextran by bacteria
(streptococcus mutant) makes dental plaque.
•Importance:-
used as plasma volume expander.

3.  When gives IV in cases of blood loses ,it
increase blood volume because, of their high
viscosity, low osmotic pressure, slow
elimination from the body ,they remain in
blood many hrs.
 Used for chromatography by gel filtration.
 Disadvantage:- can interfere with blood
grouping & cross matching, so blood sample
should be collected before IV. Of dextran.

4.  Polymer of sulfated galactose units .
 Obtained from seaweeds
 Biomedical importance :-
- Used in constipation.
- Used as culture medium for bacterial growth
& isolation.

6.  Glycoconjugates
 Heteroglycans appear in the form of
glycoconjugates.
 Proteoglycans: glycosaminoglycans + protein
 Peptidoglycans: bacterial cell wall
 Glycoproteins: O or N link to protein

7.  Heteropolysaccarides contain two or more
different kind of monosaccharides.
 They provide extracellular support for
organisms of all kingdoms: the bacteria cell
envelope, or the matrix that holds individual
cells together .
 Provides protection, shape and support to
cells, tissues and organs.

8. Heteropolysaccharides are the
most important components of the
extracellular matrix.
Hyaluronic acid, condroitin sulfates
and dermatan sulfates are important
heteropolysaccharides in the
extracellular matrix.
 These heteropolysaccharides usually
are formed by the repetition of a
monosaccharides unit of an amino
sugar and an acid sugar.

9.  Other common constituents are sulfate
groups linked to certain monosaccharides.
 heteropolysaccharides are associated with
proteins forming proteoglycans,
glycosaminoglycans or mucopolysaccharides
(since they are abundant in mucous
secretions).

10.  Glycosaminoglycans (mucopolysaccharides)
complex carbohydrates , made up of
repeating units of monosaccharides & their
content of amino sugars, either D-
glucosamine or D-galactosamine and uronic
acids, L-glucuronic acid.
GAGs contain sulphate gp or not.
structure resemble a bottle brush.

11.  Their property of holding large quantities of
water and occupying space, thus cushioning
or lubricating other structures, is due to the
large number of OH groups and negative
charges on the molecules, which by
repulsion, keep the carbohydrate chains
apart.
 Examples are hyaluronic acid, chondroitin
sulfate, and heparin

12.  Occurrence of GAGs :-
 synovial fluid of joints.
 Vitreous humour of eye
 Arterial wall
 Bones & cartilage.

13.  Composition- ( N-acetyl glucosamine-
glucuronic acid)n
 Location :- synovial fluid of joints, vitreous
humour of the eye, loose connective tissue &
umbilical cord.
 Importance:- Act as barrier in tissues
 lubricant in the synovial fluid of joints.
 strength and elasticity of cartilages and
tendons.
 Role in cell migration in embryonic tissue.
 Present in basement membrane of renal
glomeruli.

15.  Composition- (ß-1,3 N-acetyl galactosamine
so ₄ -glucuronic acid)n
 Location :- at sites of calcification in bone &
cartilage, certain neurons.
 Importance-
 Provide an endoskeletal structure helping to
maintain their shape.
 Have role in compressibility of cartilage in
weight bearing.
 strength and elasticity of cartilages, tendons,
ligaments and walls of aorta.

16.  Role in sclera of eye:- is
present in sclera of the eye
where it has an important role
in maintaining over all shape
of the eye.
 Regulate flow & concentration
of cations round the cells.

17.  Chondroitin SO ₄ A:- N-acetyl galactosamine
so ₄ -glucuronic acid)n
 Chondroitin SO ₄ B:- N-acetyl galactosamine
& L-iduronic acid)n
 Chondroitin SO ₄ C:-similar to A
 Chondroitin SO ₄ D:- isolated from cartilage
of shark

19.  Composition- (ß-1,3 N-acetyl galactosamine
so₄-L-iduronic acid)n
 Location :- skin, blood vessels, heart, lungs.
 It may be related to coagulation and vascular
diseases and other conditions.
 Role in the transparency of cornea .
 Maintain the overall shape of eye.

21.  Composition- ( N-acetyl glucosamine so₄ -
galactose )n
 Not contain uronic acid
 Two type – I , II
 Type I :- present in the cornea of the eye
 Location :- Present in cornea, cartilage bone
and a variety of other structures as nails and
hair.
 Role in the transparency of cornea.

22. Composition- ( glucosamine so ₄ -iduronic
acid so ₄ )n
 Location :-intracellular component of mast
cell, lie on the wall of arteries, heart, lungs &
skin
 It is a potent natural anticoagulant produced
in the Mast Cells that causes antithrombin
bind to thrombin and produce inhibition of
blood coagulation.

24. • Hyaluronic acid - lubricant and cushioning
substance in Joints
 Chondroitin sulfate-most abundant
glycosaminoglycan in teeth and cartilage
 Keratan sulfate - important component of
cartilage
 Heparin - blood coagulation
 Heparin sulfate - important in adhesion
between cells of the retina

25.  Glycosaminoglycans are synthesized in the ER
and Golgi. They are degraded by lysosomal
hydrolases. A deficiency of one of the
hydrolases results in a
mucopolysaccharidosis.
 These are hereditary disorders in which
glycosaminoglycans accumulate in tissues,
causing symptoms such as skeletal and
extracellular matrix deformities, and mental
retardation.

26.  Examples of these genetic diseases are
Hunter and Hurler syndromes.
 These diseases, caused by different enzyme
deficits, are characterized by physical
deformities, mental retardation and
disturbances in the degradation of heparin
sulfate and dermatan sulfate.

28.  Lactose intolerance – lack of the enzyme
lactase causes inability to digest lactose in milk
products.
 signs & Symptoms :-
 Diarrhoea & flatulence;- lactose accumulated in
the intestinal tract ,which is osmotically active
& hold water ,leads diarrhoea.
 Abdominal cramps & Distension :- lactose also
fermented by intestinal bacteria which produce
gas & leads cramps , distension.
 Diagnosis :- lactose intolerance test
 Treatment :- avoidance of milk

29. ◦ Some people are really allergic to milk.
This allergy seems to be increasing in
infants.
◦ Big Problem – calcium deficiency.
Sucrase deficiency
Disacchariduria :- disaccharides appear
in the urine.
Monosaccharides malabsorption:
monosaccharides are deficient in the
body.
Causes:- due to absence of transport
protein.

31.  A new born baby had severe abdominal
distension , abdominal pain and diarrhea
after being fed breast milk . Stool analysis
revealed the presence of reducing sugar .
1. What is your diagnosis?
2. What is the enzyme defect?
3. Enumerate all reducing sugars?
4. How can it be treated ?

32.  mucopolysaccharidoses (MPS) are a group of
inherited lysosomal storage disorders.
 In individuals with MPS disorders, deficiency or
malfunction of specific lysosomal enzymes leads to
an abnormal accumulation of certain complex
carbohydrates (mucopolysaccharides or
glycosaminoglycans) in the arteries, skeleton, eyes,
joints, ears, skin, and/or teeth.
 These accumulations may also be found in the
respiratory system, liver, spleen, central nervous
system, blood, and bone marrow.

33.  Individuals with MPS disorders share many similar
symptoms such as multiple organ involvement,
“coarse” facial features, and abnormalities of the
skeleton especially joint problems.
 short stature, heart abnormalities, breathing
irregularities, liver and spleen enlargement
(hepatosplenomegaly), and/or neurological
abnormalities.

34.  most severe form of mucopolysaccharidosis.
 Deficiency of the enzyme :- alpha-L-iduronidase
 Biochemical defect:- in an accumulation of
dermatan and heparan sulfates.
 Symptoms :- Affected infants may experience
developmental delays, recurrent urinary and
upper respiratory tract infections, noisy
breathing and persistent nasal discharge.
 large tongue, severe deformity of the spine, and
joint stiffness. Mental development begins to
regress at about the age of two.

35.  Inheritance:- X-linked trait.
Enzyme deficiency :- Iduronate sulphatase
 Accumulation of heparin sulfate may occur
progressive growth delays, resulting in short
stature; joint stiffness, with associated restriction
of movements; and coarsening of facial features,
including thickening of the lips, tongue, and
nostrils.
 Affected children may also have an abnormally
large head (macrocephaly), a short neck and
broad chest, delayed tooth eruption, progressive
hearing loss, and enlargement of the liver and
spleen (hepatosplenomegaly).

36.  MPS III) has four subtypes (A, B, C, and D)
 Accumulation of heparan sulfate may occur.
 Symptom:- hyperactivity, sleep disorders, and
delays in attaining developmental milestones
(e.g., crawling and walking).

37.  exists in two forms (Morquio syndromes A and B)
 Deficiency of the enzyme :- N-acetyl-
galactosamine-6-sulfatase and beta-galactosidase,
 resulting in accumulation of keratan and
chondroitin sulfate in type A and keratan sulfate in
type B.
 clinical features :-
 growth retardation, a prominent lower face, an
abnormally short neck, knees that are abnormally
close together (knock knees ) flat feet, abnormal
sideways and front-to-back or side-to-side
curvature of the spine , abnormal development of
the growing ends of the long bones (epiphyses). In
some cases, hearing loss, weakness of the legs,
and/or additional abnormalities also occurs.

38.  Hurler and Scheie syndromes occur due to a
deficiency of the same enzyme.

39.  Deficiency of the enzyme N-
acetylgalactosamine-4-sulfatase, resulting in
accumulation of dermatan sulfate.
 Symptoms :- coarse facial features, umbilical
hernia, a prominent breast bone (pectus
carinatum), joint contractures, clouding of the
corneas, and an abnormal enlargement of the
liver and/or spleen (heptasplenomegaly).

40.  Deficiency of the enzyme beta-glucuronidase,
 Accumulation of three glycosaminoglycans:
dermatan sulfate, heparan sulfate and
chondroitin sulfate.
 mild to severe intellectual disability, skeletal
abnormalities , Hernias, clouding of the
corneas, excessive accumulation of
cerebrospinal fluid in the skull
(hydrocephalus), short stature, heart disease,
and coarse facial features .

41.  described in a single individual with clinical
and biochemical features of Morquio and
Sanfilippo syndromes.
 deficiency of glucosamine-6-sulfate
sulfatase.

42.  rare form of MPS
 Deficiency of the enzyme :- hyaluronidase,
which is needed to breakdown the
mucopolysaccharides known as hyaluronan
 Symptoms :- mild short stature, cysts,
frequent ear infections, cleft palate, and the
development of soft-tissue masses.

43.  Are protein to which oligosaccharides are
covalently attached to their polypeptide
chain.
 Contain much shorter carbohydrate chain
than proteoglycans.
 Glycoprotein contain less than 4%
carbohydrate in the molecule.
 Mucoprotein contain more than 4%
carbohydrate .

44.  All the plasma proteins of human are
glycoproteins.
 Serve as hormones, eg;- chorionic
gonadotropin, thyroid stimulating hormone
(TSH)
 Serve as enzymes ,eg:- alkaline phosphates.
 Act as antibodies, eg; Igs, histocompatibility
antigens.
 Act as structural component , eg:- collagen.

45.  Role as lubricant & protective agent.
 Role as transport molecules. Eg:- transferrin
& ceruloplasmin.
 Play role in cell surface recognition sites.
 Also act as cell surface antigen.
 Vitamin B 12 absorption ----intrinsic factor
 Blood clotting-- –fibrinogen
 Angiotensin converting enzyme-2 :- is a
glycoprotein with 805 aminoacids. It acts as
receptor for the spike protein S1 of SARS-
COV-2 viral entry into the cell.