Biology 10.3 Starch, Glycogen and Cellulose

Starch

= polysaccharide, found in parts of plants in form of small grains.

Large amounts occur in seeds and storage organs.

Made up of chains of a-glucose monosaccharides, linked by glycosidic bonds formed in condensation reactions.

Unbranched chain wound into tight coil that makes molecule very compact.

Main role = energy storage, suited for because:

• Insoluble - doesn't draw water into cells by ososis.
• Insolubility means it doesn't easily diffuse out of cells easily.
• Compact, can be stored in small space.
• When hydrolysed forms a-glucose which is easily transported and used in respiration.

Starch is never found in animal cells.

Glycogen

Similar to starch but has…