A patient of diabetes mellitus excretes glucose in urine even when he is kept on a carbohydrate free diet because:
Fats are catabolised to form glucose
The correct option is A:
Explanation of the correct option :
In diabetes mellitus, the patient is unable to secrete insulin. The glucose is excreted out. Even if the diet is carbohydrate-free, the body will convert glycogen and fatty acids reserves into glucose, which is the energy molecule in the body, that the cells can utilize. However, in the absence of insulin, the cells are unable to uptake the glucose and hence, it will circulate in the blood once it reaches high concentrations, the body filters it out via the kidneys, hence their excretion in urine.
Explanation of the incorrect option:
Option B:
Catabolism of amino acids does not produce glucose.
Option C:
The presence of amino acids in the bloodstream does not cause glycosuria.
Option D:
Glycogen in the bloodstream can not be catabolized into glucose.
Final answer: A patient with diabetes mellitus excretes glucose in urine even when he is kept on a carbohydrate-free diet because the body will convert glycogen and fatty acids reserves into glucose.