1) one difference between carbohydrates and lipids is that a) lipids will dissolve in water but not carbohydrates. b) carbohydrates will dissolve in water but not lipids. c) carbohydrates contain hydrogen, carbon, and oxygen and lipids do not. d) lipids contain hydrogen, carbon, and oxygen and carbohydrates do not.

Both carbohydrates and lipids have very many independent biological functions.
Simple carbohydrates (sugar, glucose, fructose etc) are the main source of immediate energy. That is, they are metabolized easily and quickly. All our cells can use glucose for energy, so once it is metabolized and reaches the blood stream it can travel to other cells and tissues.However, lipids are good for storage. The fact that they are insoluble in water makes helps in this cause,  and also they can provide twice as much energy (or more) as some carbohydrates