WJEC AS Level Biology: Polysaccharides (Homework task)

When are polysaccharides formed?

When many glucose units join together and include:

• Glycogen and starch. Which are both formed by the condensation of alpha glucose

• Cellulose formed by the condensation of Beta Glucose

Starch is a mixture of which 2 polysaccharides?

Amylose and amylopectin

What is amylose?

Amylose is an unbranched chain of glucose molecules joined by 1, 4 glycosidic bonds, resulting in amylose being coiled and thus is a very compact molecule, meaning it can store a lot of energy

What is Amylopectin?

Amylopectin is branched and is made up of glucose molecules joined by 1, 4 and 1, 6 glycosidic bonds, due to the presence of many side branches it is rapidly digested by enzymes, therefore energy is released quickly

Polysaccharide is one of the saccharides, what are the other 3?

Monosaccharides and disaccharides.

What Type of reactions from Polysaccharides?

Condensation Reactions

What is Chitin?

It is a polysaccharide made of chains of beta glucose monomers, with amino acid side chains - one OH groups of each beta glucose molecule is replaced with an amino acid.

What are some properties of chitin, and where is it used?

It is Lightweight and Strong, it is used to form the exoskeletons of insects.

What is Cellulose?

A polymer of B-glucose, adjacent monomers twisted through 180° to each other, allowing hydrogen bonds between chains.

What are microfibrils?

A strong structure for plant cell walls, 60-70 of them make up a structure called fibres.