Final answer:
Carbohydrates provide immediate energy, mainly in the form of glucose, while lipids serve as a compact energy reserve and are also critical for cell membranes and the absorption of fat-soluble vitamins.
Step-by-step explanation:
Carbohydrates and lipids both serve as essential sources of energy for organisms. Carbohydrates, such as glucose produced by photosynthesis, are the main source of immediate energy needs and are typically stored in forms like starch and glycogen. On the other hand, lipids, which include fats and oils, provide a more concentrated form of energy, supplying about 9 kcal of energy per gram, which is more than twice that of carbohydrates. Lipids not only serve as major energy reserves stored in a compact form, but also play crucial roles in cell membrane structure, insulating and protecting organs, and are necessary for the absorption of fat-soluble vitamins.