Which of the following statements is false?
a) the amino acid pool is the body's total supply of amino acids in the body's proteins.
b) amino acids can be used to supply energy only after being converted to a citric acid cycle intermediate.
c) fats and carbohydrates are oxidized directly to produce cellular energy.
d) excess carbohydrate and fat can be stored as such, whereas excess amino acids are oxidized for energy or converted to fat or glycogen for storage.