Question

AT1 simultaneously transports tryptophan against its concentration gradient and a sodium ion along its concentration gradient into the cytoplasm of intestinal epithelial cells. Which amino acid, in addition to tryptophan, is most likely to be transported by AT1?

1) phenylalanine
2) lysine
3) arginine
4) glutamate

Answer 1

Phenylalanine is the amino acid most likely to be transported by AT1 along with tryptophan, as they are both large neutral amino acids and can be transported by similar carriers such as LAT1.

Step-by-step explanation:

The amino acid most likely to be transported by the AT1 along with tryptophan is phenylalanine. AT1 is known to transport large neutral amino acids. Since both tryptophan and phenylalanine fall into the category of large neutral amino acids, it is logical to conclude that AT1 could transport phenylalanine in addition to tryptophan. This is in line with the functioning of the L-type amino acid transporter (LAT1) which is responsible for transporting similar types of amino acids, including phenylalanine, into cells.