Final answer:
Glucose is the carbohydrate used as an immediate source of energy by the body. Starch is a plant-derived carbohydrate with a linear structure, while glycogen, found in animals and humans, has a highly branched structure for rapid glucose release. Starch is digested slower than glycogen, which is synthesized in the body to store excess glucose.
Step-by-step explanation:
The carbohydrate that can be used by the body as an immediate source of energy is glucose. During digestion, carbohydrates are broken down into glucose, which is then used by cells to create adenosine triphosphate (ATP), the energy currency of the cell.
Now, considering the difference between starch and glycogen, both are storage forms of glucose. Starch is typically found in plants and is made up of a large number of glucose units bonded together. It is an important dietary source of carbohydrate for humans. Glycogen, on the other hand, is the storage form of glucose in animals and humans. It is stored in the liver and muscle tissues, and it can quickly be broken down into glucose when needed for energy.
The structure of glycogen is highly branched, which allows for rapid release of glucose, whereas starch has a more linear structure with fewer branches, which makes its breakdown slower. This structural difference is crucial as it affects the digestion rate and the subsequent availability of glucose for energy. Moreover, while both starch and glycogen serve as energy reserves, starch is a primary source in our diet, while glycogen is synthesized by our bodies to store excess glucose.