What is a single straight chain starch molecule called?

Amylose is the correct answer because it is a type of polysaccharide that consists of a single, unbranched, straight chain of glucose molecules linked together primarily by α(1→4) glycosidic bonds. This structural characteristic makes amylose distinct from amylopectin, which is a branched starch molecule containing both α(1→4) and α(1→6) linkages. Glycogen is another polysaccharide that serves as a form of energy storage in animals, and similar to amylopectin, it has a highly branched structure. Cellulose, while also a polysaccharide made up of glucose, consists of β(1→4) linkages and serves as a structural component in plant cell walls. Therefore, when specifically referring to a single straight chain starch molecule, amylose is the appropriate designation.