Question

Two of the facts which differentiate lipids and carbohydrates from amino acids are that, amino acids can neither be stored nor excreted.

true

false

A baby got sick a few weeks after birth and test results show that the baby had higher than normal levels of the amino acid phenylalanine. Which of the following best describes the baby's probable diagnosis?

		The baby has maple syrup disease
		The baby has PKU
		More lab test are needed to confirm the cause malady
		The baby is fine. The phenylalanine will clear from the blood with time.

Maple syrup disease is largely cause by a defect in the biosynthesis of branched-chain amino acids such as isoleucine.

True

False

Individuals with defects in ammonia clearance tend to suffer neurological problems due to influx of calcium ions into the brain.

True

False

Uridylylation of PII stimulates the formation of glutamine from glutamate.

True

False

Answer 1

1) Two facts that differentiate lipids and carbohydrates from amino acids are amino acids can neither be stored nor be excreted.

The statement is False. Though the amino acids are not stored inside body unlike carbohydrates and lipids, they can be excreted if produced in excess by the body.

2) The probable condition with which the baby is diagnosed is that, The baby has PKU, which is treated by taking diets that have very low Phenylalanine content.

If the baby had maple syrup disease, other brached chain amino acids (BCAA) such as isoleucine, valine, leucine and methionine levels would also be high apart from the phenylalanine levels, which is not so.

3) Maple syrup disease is largely caused by a defect in the biosynthesis of branched-chain amino acids such as isoleucine.

The statement is true.

4) Individuals with ammonia clearance tend to suffer neurological problems due to the influx of calcium ions into the brain.

The statement is false because, the non clearance of ammonia leads to the water movement (not calcium ions) into the astrocytes of the brain causing low grade cerebral edema.

5)Uridylylation of PII stimulates the formation of glutamine from glutamate.

The statement is false, since the glutamine formation from glutamate and ammonia is a condensation reaction that requires phosphate from ATP and not uridine.