What molecule am I?
If you’re making gravy for your Thanksgiving meal, you’ll need some starch. Also, called amylum, starch is the component of plants that stores energy, much as animals store fats. Corn, wheat, and potatoes are especially rich in starch.
Starch consists of complex carbohydrates; the most abundant are amylopectin (≈70–80 wt% of starch) and amylose1 (the remaining ≈20–30 wt%). Both constituents are made up of chains of α-D-glucopyranosyl units. The difference between the two is that amylopectin is a branched-chain polymer that contains 1→4 and 1→6 α-D-glucopyranosyl linkages. Amylose is a helical polymer with only 1→4 α-D-glucopyranosyl linkages.
Amylopectin and amylose are insoluble in water; but as starch they do an excellent job of thickening and stabilizing water-based mixtures such as gravy, sauces, and soups. Amylopectin has excellent film-forming properties and is used to make edible food coatings. Its presence in starch also makes it useful for sizing textiles; it adds rigidity by reordering into crystalline structures. Science Direct has more information about the chemistry and uses of amylopectin.
When you’re preparing your favorite gravy recipe for your Thanksgiving stuffing, remember that it’s the amylopectin that makes it possible.
Learn more about this molecule from CAS, the most authoritative and comprehensive source for chemical information.