(a) What is meant by the term fuel value? (b) Which is a greater source of energy as food, \(5 \mathrm{~g}\) of fat or $9 \mathrm{~g}$ of carbohydrate? (c) The metabolism of glucose produces \(\mathrm{CO}_{2}(g)\) and \(\mathrm{H}_{2} \mathrm{O}(l)\). How does the human body expel these reaction products?

Fuel value is the amount of energy that is released when a specific amount of a substance (usually food) is burned or metabolized in the body. This value is typically measured in units of energy, such as calories or joules.

To answer this question, we need to know the energy provided by 1 g of fat and 1 g of carbohydrate. 1 g of fat provides approximately 9 calories of energy. 1 g of carbohydrate provides approximately 4 calories of energy. Now, let's calculate the total energy provided by 5 g of fat and 9 g of carbohydrate. Energy from 5 g of fat = 5 * (9 calories/g) = 45 calories Energy from 9 g of carbohydrate = 9 * (4 calories/g) = 36 calories Thus, 5 g of fat provides a greater source of energy as food compared to 9 g of carbohydrate.

The metabolism of glucose results in the formation of carbon dioxide (CO2) and water (H2O). The human body gets rid of these reaction products in the following ways: 1. Carbon dioxide (CO2): It is expelled from the body through the respiratory system. During exhalation, lungs remove the carbon dioxide from the body, which is then replaced with oxygen during inhalation. 2. Water (H2O): Water produced from glucose metabolism is expelled from the body through various processes, including sweating, urination, and respiration. Sweat glands release excess water and salts through sweating, and the kidneys filter and expel water and waste products through urination. Additionally, a small amount of water is also expelled during exhalation along with carbon dioxide.