Cellulose : the major structural component of plants, especially wood and plant fibers - PowerPoint Presentation

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Cellulose

:

the major structural component of plants, especially wood and plant fibers

a linear polymer of approximately 2800 D-glucose units per molecule joined by b-1,4-glycosidic bondsfully extended conformation with alternating 180° flips of glucose unitsextensive intra- and intermolecular hydrogen bonding between chains

Polysaccharides

Cellulose is important source of energy for animals

And it is very important for our digestive system .

It contains glucose but different in linkage beta (1-4)

Cellulose

also decrease absorption of lipids (fat) and cholesterol , so it decrease cancer risk , because cancer increase by increasing fat and

consumption of protein

decrease cholesterol , decrease artery thersosis , decrease cardiovascular disease , weight decreaseCellulose is digestive by animals because they have cellulase

enzyme in bacteria which located in their digestive system

Carbohydrates – Complex (Polysaccharides)

Cellulose = polysaccharide

found in plant

cell walls

Cellulose fibers

Macrofibril

Microfibril

Chains of

cellulose

Starch

A

polymers of

a-D-glucose units and used for energy storage in plants, 2 formsamylose: continuous, helical unbranched chains of up to 4000 a-D-glucose units joined by

-1,4-glycosidic bonds

amylopectin: a highly branched helical polymer consisting of 24-30 units of D-glucose joined

by



_

1,4-glycosidic

bonds and branches created by -1,6-glycosidic bondsamylases catalyze hydrolysis of -1,4-glycosidic bondsdebranching enzymes catalyze the hydrolysis of -1,6-glycosidic bonds

Amylase found in saliva

And there are two type:-

Salivary amylase and pancreatic amylase .

both are the same but pancreatic amylase continue to digest what salivary amylase that begin to digest it .

Starch

Polysaccharides

Branching in

amylopectin and glycogen

Glycogen is the energy storage of glucose in animals , and we find it in muscles and liver .

It is highly branched and globular .

It is highly branched to decrease the storage space , and it is easy to dissociated and to synthesis.

Our body use the storage of glycogen when we do exercise ( in muscles ) or fasting(in liver) .In case of hypocalcemia? When blood sugar level decrease the glycogen will give blood to body to rest of body .*Blood glucose necessary for brain

Cellulose

, chitin and starch are all called

homo

polysaccharides

Polysaccharides

Chitin:

the major structural component of the exoskeletons of invertebrates, such as insects and crustaceans; also occurs in cell walls of algae, fungi, and yeasts

composed of units of N-acetyl--D-glucosamine joined by -1,4-glycosidic bonds

Polysaccharides

Bacterial cell walls:

prokaryotic cell walls are constructed on the framework of the repeating unit NAM-NAG joined by

b-1,4-glycosidic bonds

Bacterial Cell Walls

The N-acetyl-D-

glucoseamine

and N-acetylmuramic acid polysaccharide is in turn cross-linked by small peptidesin Staphylococcus aureus, the cross link is a

tetrapeptidethis tetrapeptide

is unusual in that it contains two amino acids of the D-series, namely D-Ala and D-Glneach tetrapeptide is cross linked to an adjacent

tetrapeptide

by a

pentapeptide

of five

glycine

unitsPeptidoglycan: is the resulted cross linking of polysaccharides by peptides

Bacterial

Cell Walls

Bacterial Cell Walls

The

peptidoglycan of a bacterial cell wall

Staphylococcus

aureus

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