Polysaccharides

Homoglycans (homopolysaccharides)

only one type of sugar.

Heteroglycans (heteropolysaccharides)

have more than one type of sugar.

Homoglycans such as amylose and amylopectin are

starches in plants

glycogen in animals is a

homogylican

Proteoglycans

macromolecules with one or more polysaccharides containing glycosamines joined to a protein

Glycoproteins

one or several oligosaccharides of varying complexity covalently joined to a protein; exact arrangement of sugar units and their modifications constitute identity elements for cell

Glycolipids

membrane sphingolipids in which the hydrophobic head groups are complex oligosaccharides

storage homoglycans

amylose, amylopectin, glycogens

(1→4), (1→6) (branches)

Amylopectin and glycogen

Structural homoglycans

cellulose and chitin

B(1 through 4) is both

chitin and cellulose

10 to 30 percent of polysaccharides are

amylose

70 to 90 percent of total plant polysaccharides are

amylpectin

alpha amylase

an endoglycolase, acts only on interior 1→4 glycosidic bonds

beta amylase

an exoglycolase, acts on non-reducing ends, releasing maltose, acts only on 1→4 glycosidic bonds

amylopectin structure contains both

1-4 and 1-6 glycosidic bonds at branch points

the strength of cellulose fibrils comes from

packing of cellulose and stabilixation by h-bonding between the polymers

The beta glycosidase enzyme cellulase can hydrolyze

beta (1→4) covalent bond, amylases can not.

chitin is a homoglycan of

N-acetylglucosamine and serves as a part of exoskeltons

chitin shows glycosidic bonds

beta-(1→4)

chitin is

linear, straight and extended

Proteoglycans are complexes of proteins and

glycosamonoglycans

proteoglycan fill the space

between cells in an organism

hyaluronic acid

the basis of important macromolular proteogylcan complex in fluid of joints and in cartilage

proteoglycans in cartilage contain

sulfated sugars

link proteins bind

aggrecan proteins to create cartilage

cartilage matric is composed of

1. collagen fibrils,

2. proteoglycans,

3. water

peptidoglycans are found in

bacertial cell walls