Polysaccharides 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 bonds fully extended conformation with alternating 180° flips of glucose units extensive intra- and intermolecular hydrogen bonding between chains

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 decrease Cellulose is digestive by animals because they have cellulase enzyme in bacteria which located in their digestive system

Carbohydrates – Complex (Polysaccharides) Cellulose = polysaccharide Cellulose fibers Cellulose = polysaccharide found in plant cell walls Macrofibril Microfibril Chains of cellulose

Starch A polymers of a-D-glucose units and used for energy storage in plants, 2 forms amylose: 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 bonds amylases catalyze hydrolysis of -1,4-glycosidic bonds debranching enzymes catalyze the hydrolysis of

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 The difference between amylopectin and glycogen is no. of branches Glycogen every 10 Amylopectin every 25

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 homopolysaccharides

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 peptides in Staphylococcus aureus, the cross link is a tetrapeptide this tetrapeptide is unusual in that it contains two amino acids of the D-series, namely D-Ala and D-Gln each tetrapeptide is cross linked to an adjacent tetrapeptide by a pentapeptide of five glycine units Peptidoglycan: 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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