Starches

Not all starch molecules are alike, however. Glucose units in starch can be arranged in one of two ways: either as long, straight chains or as short but highly branched ones. Straight-chain starch molecules are called amylose, while the much larger, branched starch molecules are called amylopectin (Figure 12.4). Although amylose is a straight chain, the chain typically twists into a helical shape, while amylopectin, with its many branches, looks like a flat coral fan. Whether amylose, amylopectin, or a mix of both, starch molecules are tightly packed in an orderly fashion inside starch granules.