Which of the following statements about fatty acids (triglycerides) is true?
A. Saturated fatty acids contain one or more double carbon bonds.
B. Most fatty acids in nature have an even number of carbon atoms.
C. Fats yield approximately 50% as much energy as do carbohydrates in humans.
D. Most fats containing unsaturated fatty acids are solids at room temperature, whereas fats containing saturated fatty acids are liquids.
Saturated fats have all their carbon bonds saturated with hydrogen. Because of this, there are no double bonds. As the number of double bonds increases, the melting point of the fat decrease. Therefore, saturated fats are normally solids at room temperature, whereas unsaturated fats are liquids. Complete oxidation of 1 g. of fat yields about 9 calories, whereas 1 g. of carbohydrate yields about 4 calories.