Carbohydrate metabolic enzymes bind d-glucose specifically. d-glucose has an estimated caloric value of 1 k. cal per 4 grams of carbohydrate.
based on the methods used to convert the energy of d-glucose into a useable form, what would you estimate the caloric value of l-glucose to be using the same method?

a) 1 k. cal per 4 grams
b) 1 k. cal per 2 grams
c) 1 k. cal per 8 grams
d) 0 k. cal per 4 grams
e) 2 k. cal per 8 grams

D) 0 k.cal per 4 grams

Explanation:

Genarally, glucose can be classified into two enantiomers such as d-glucose and l-glucose. The d-glucose is the most common sugar that bodies of living organisms use as source of energy. However, l-glucose is an organic compound and it is one of the aldohexose monosaccharides. It is the l-isomer of glucose and commonly refer to as a low-calorie sweetener. The l-glucose is  relatively indistinguishable in taste from d-glucose but cannot be used as a source of energy. Therefore, in the given problem:

if d-glucose has an estimated caloric value of 1 k.cal per 4 grams of carbohydrate, then the caloric value of l-glucose will be 0 k.cal per 4 grams.