Final answer:
Plants use starch as their principal energy storage molecule, while animals use glycogen and fats. Starch consists of amylose and amylopectin, and glycogen is a more highly branched glucose polymer stored in liver and muscle tissues.
Step-by-step explanation:
The principal energy storage molecules for plants and animals are different. Plants primarily use starch molecules for their storage needs. Starch contains two types of polymers made of glucose units: amylose, which is linear, and amylopectin, which has a branched structure.
Animals store energy using different molecules, such as glycogen and fats. Glycogen is similar to starch in branching structure but is more highly branched and is primarily found in the liver and muscle tissues. It acts as a rapid release energy source when glucose levels in the blood are low. Fats, including triglycerides, store energy more compactly and are used by animals as a long-term energy reserve.