Starch and Cellulose.pptx

1. Starch
• Starch is a storage polysaccharide stored by plant
cells for later use
• Plants store starch as granules within cellular
structure known as plastids
• Most of the glucose monomers in starch are joined
by 1- 4 glycosidic linkage
• Starch contains two types of glucose polymers
amylose and amylopectin
• Amylose is long unbranched chain of glucose
molecules connected by 1 – 4 linkage
• Amylopectin is highly branched, the linkage joining
successive molecules of glucose is 1- 4 type,
however the branch points are 1- 6 linkage

2. Starch

3. Cellulose
• Cellulose is a structural polysaccharide and a major
component of plant cell wall
• It is the most abundant organic compound on Earth
• Cellulose is also a polymer of glucose with 1- 4
glycosidic linkage
• Monomeric unit in cellulose is β-glucose whereas
that in starch is α-glucose
• Alpha and beta glucose differs in the position of
hydroxyl group attached to number 1 carbon
• Unlike some starch molecules cellulose molecule is
straight and is never branched

4. Cellulose