Animals do not have enzyme systems to efficiently break down fat and extract energy from it. While animals can use carbohydrates and proteins as sources of energy, they lack the necessary enzymes to fully metabolize fat. Fat digestion and absorption in animals require the enzyme lipase, which breaks down fats into fatty acids and glycerol. Animals like humans have the ability to produce lipase, but it is not as efficient as in organisms specialized in fat metabolism, such as some bacteria. On the other hand, animals have well-developed enzyme systems to make use of energy from carbohydrates, proteins, and water. Carbohydrates are broken down into glucose, which is then metabolized to produce energy. Proteins are broken down into amino acids, which can be used for energy production. Water, while not directly providing energy, is essential for various metabolic processes in animals.