Describe why lipids are so important to cellular evolution.

Lipids are essential to your health because they support a number of your body’s functions. Lipids enable the fat-soluble vitamins A, D, E, and K to be absorbed from food and regulate cholesterol metabolism. Lipids are made up of several fatty acids (containing long chains of carbon and hydrogen atoms), bonded to a glycerol. They are typically triglycerides, which have three fatty acids attached to one glycerol. Lipids have the highest caloric value of any nutrient. One gram of lipids provides 9.3 k. cal. of energy. Lipids are insoluble in water. They are stored in your body as reserve food, which you can use when you need it. Lipids form an insulating layer that helps maintain body temperature. The myelin sheaths around your nerves contain lipids that prevents the passage of nerve impulses to adjacent nerve fibers. Lipids are also structural components of your cells, and their presence is required for certain enzymes and hormones. 

Hydrosphere is the correct answer