Hartnup disease is due to defective transport of -

Ans. is 'd' i.e., Tryptophan Hartnup diseaseo It is an inherited disorder in the metabolism of tryptophan.o It is due to defective transport of tryptophan and other neutral amino acids in the intestine and kidneyo This results in deficiency of tryptophan leading to decreased synthesis of niacin and serotonino Thus there are pellagra (niacin deficiency), neurological symptoms (serotonin deficiency) and amino aciduria due to defective transport of amino acids in kidney.