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. |