BE.342/442 Thursday, November 3, 2005
Topic: Polysaccharides and Oligosaccharides
Next Tuesday, Prof. Zhang will be out of town, but we’ll play a movie about Francis Crick.
Please come on time, because the movie is 2 hours long.
On November 15
, Prof. Zhang will be out of time, but we’ll have a guest lecture about self-
At the end of this lecture, we’ll look at Peter Seeberger’s work, featured on the cover of last
. He has synthesized sugars from scratch in his lab!
We’ve spent many lectures on proteins, and last time, we discussed lipids as a biomaterial.
Today, we’ll discuss another important class of materials built from sugars.
Polysaccharides and oligopolysaccharides can be divided into two classes:
Homopolysaccharides: cellulose (plant structures), starch (plant energy storage), chitin
(exoskeletons of animals like lobsters)
Heteropolysaccharides: hemicellulose, hyaluronic acid, heparan sulfate, etc.
Their functions include:
Storage: starch, glycogen
Structural: cellulose, hemicellulose, chitin
Signaling: glycoproteins, lipopolysaccharides, glycolipids
Sugars arte difficult to synthesize in the lab, can be obtained from organisms, which construct
and are then chemically manipulated. Sugars serve as the building blocks of polysaccharides.
is a mixture of glucans than plants synthesize as their principal food reserve. It is
deposited as insoluble granules composed of alpha-amylose and amylopectin.