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1.)Which of the following is NOT employed in cholesterol synthesis regulation?

Group of answer choices

 

 

Genetic regulation of the reductase mRNA

 

Feedback regulation by cholesterol

 

All presented answers

 

NAD+ levels

 

Translational control by mevalonate intermediates

 

 

 

2.)Transmission of ammonia throughout the body requires a specific carrier that is derived from the result of ammonia capture. From the list below select the correct: capture/transmission pair.

 

Alanine / Pyruvate

 

Glutamate / Glutamine

 

a-ketoisovalerate / valine

 

Glutamine / Glutamate

 

Glutamine / Pyruvate

 

 

3.)(True/False) A patient, sensitive to nitrogen overload, presents with deficiency of amino-acid threonine. One method to correct this problem and to avoid exacerbating the nitrogen overload is to increase the amount of the a-keto form of theronine the patient ingests.

Group of answer choices

 

 

True

 

False

 

 

4.)(True/False) In the metabolism of amino-acids in the cell, phenylalanine is converted to tyrosine but the backwards reaction cannot occur. In other words, tyrosine cannot be directly converted phenylalanine by phenyalanine hydroxylase.

Group of answer choices

 

 

False

 

True

 

5.)Consider potential deficiencies of two urea cycle enymes: Carbamoyl Phosphate Synthetase I (CPSI) and Argininosuccinate Synthetase (AS). A person with a CPSI deficiency must be placed on a diet highly restricted in amino acid intake and has a life threatening condition. However, a person with AS deficiency actually requires a diet supplemented with arginine and this condition is not life threatening! Why?

Group of answer choices

 

 

A.) With AS deficinecy the kidneys can perform the urea cycle instead of the liver, thus this is not life threatening.

 

B.) With AS deficiency there is no ammonia capture, thus the patient needs arginine supplementation or risk amino acid deficiencies.

 

C.) With CPSI deficiency excess arginine is produced leading to amino acid overload.

 

D.) With CPSI deficiency there is no capture of free ammonia, thus there is a risk of ammonia overload.

 

E.) With CPSI deficiency the kidneys generate arginine in excess leading to over-sequesteration of ?-ketoarginate and shutdown of the Electron Transport Chain.