Question

One of these animals excretes amino acid without deamination.
a. Rat
b. Earthworm
c. Unio
d. Fly

Answer 1

Hint: Deamination is an important process in which an amino group is transferred from an amino acid which presents as a donor, to a keto acid which acts as an acceptor, allowing the transfer of amino acids to alpha keto acids for excretion. Deaminases are the enzymes that catalyse this reaction.

Complete answer:
• Certain invertebrates like some unio, and some echinoderms excrete out excess amino acid as such without undergoing any deamination, these animals are called ammonotelic.
• The elimination of nitrogenous waste in the form of amino acids is called an aminotelism.
• Anaerobic metabolism results in the accumulation of the amino acids like an alanine and the glutamate inside the cell.
• During the hypo-osmotic stress the cells have more concentration of salts or solutes than its surrounding.
• The intracellular concentrations that are present in the amino acids decrease by the process of extrusion from the cells followed by the deamination or excretion.
• Due to this reason the amino acids are excreted directly as a part of osmoregulation in a marine unio and echinoderms under the salinity stress.

Hence, the correct answer is option (B).

Additional information:
• The examination is the removal of an amino group from a molecule.
• In the human body, the deamination takes place primarily in the liver, it can also occur in the kidney.
• When there is a situation of excess protein intake present, deamination is the process that is used to break down the amino acids for energy.

Note: The urea is produced during the Deamination and is eliminated as the Waste Product. Ammonia that is formed as a byproduct is released during the deamination is removed from the blood almost entirely by the conversion into urea in the liver. This occurs through another metabolic process called as the urea cycle