Lecture 47 Flashcards Preview

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Flashcards in Lecture 47 Deck (10)
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1
Q

Ammonia is very toxic, especially to the _____. The serum level is regulated around _____microM/L by two key enzymes, _______ and _______ because ______ is a major source of ammonia and ______ is a major sink for ammonia.

A

Ammonia is very toxic, especially to the CNS. The serum level is regulated around 35microM/L by two key enzymes, GLUTAMINE SYNTHETASE and GLUTAMINASE, because GLUTAMINE is a major source for ammonia and GLUTAMATE is a major sink for ammonia.

2
Q

The expression of Glutamine synthetase and Glutaminase is tissue specific. The kidneys, intestines, and periportal hepatocytes produce _______ but not ______ ______. The brain, muscles, and perivenous hepatocytes produce ______ ______ but not ______.

A

The kidneys, intestines, and periportal hepatocytes produce GLUTAMINASE but not GLUTAMINE SYNTHETASE. The brain, muscles, and perivenous hepatocytes produce GLUTAMINE SYNTHETASE but not GLUTAMINASE.

3
Q

_____ provides a nontoxic storage and transport form of ammonia, and it is generated from the conversion of _____ in a reaction that requires ATP + NH4 and is catalyzed by _____ _____.

A

GLUTAMINE provides a nontoxic storage and transport form of ammonia, and it is generated from the conversion of GLUTAMATE in a reaction that requires ATP + NH4 and is catalyzed by GLUTAMINE SYNTHETASE.

4
Q

Formation of Urea takes place in the _____, specifically within ______ hepatocytes, and is the most important disposal route for ammonia.

A

Formations of Urea takes place in the LIVER, specifically in PERIPORTAL hepatocytes, and is the most important disposal route for ammonia.

5
Q

The sources of Nitrogen in the Urea cycle are as follows: One molecule of N comes from ____ and the other comes from ______ acid.

A

One molecule comes from NH3 (ammonia), and the other comes from ASPARTIC ACID.

6
Q

There’s a similarity in the Urea formation pathway to pyrimidine synthesis. Both have a ____ source, HCO3, and _____.

A

Both have a NITROGEN source, HCO3, and ATP.

7
Q

Carbamoyl Phosphate synthetase I has an absolute requirement for N-acetyl _______.

A

N-AcetylGLUTAMATE

8
Q

The Urea cycle is regulated by the activation of N-acetyl glutamate synthetase via the AA ______.

A

ARGININE.

9
Q

CPS 1 deficiency is the most severe cause for ______, whereas _____ deficiency is the most common.

A

Most sever cause for HYPERAMMONEMIA, whereas OtC deficiency is the most common.

10
Q

Hyperammonemia can be treated with _________, which is converted to _______, and can shunt glutamine to the urine by binding it, thereby getting rid of ammonia from the body.

A

It can be treated with PHENYLBUTYRATE, which is converted to PHENYLACETATE, and can shunt glutamine to the urine by binding it.