Differences between glycogen and starch

S.N.

Glycogen

Starch

1. It is the main reserve food material of animal cells, hence also called animal starch. It is the main reserve food material in plant cells and is also called amylum.
2. Its molecule is much branched. It consists of two components; amylose (unbranched) and amylopectin (much branched).
3. Its molecule consists of about 30,000 glucose units. Its amylopectin has 200-2,000 glucose units, whereas amylopectin has 2,000-2,00,000 glucose units.
4. It gives reddish brown color with iodine. It gives deep blue color with iodine.
5. It is stored in liver and muscle cells. It is stored in seeds, grains, tubers and fruits.
6. Glycogen grains are stored in the cytoplasm, usually associated with smooth endoplasmic reticulum. Starch grains are stored in plastids (chloroplasts and amyloplasts).
7. Glycogen grains have almost uniform shape and structure. The form and structure of starch vary with the source.

Differences between glycogen and starch