Chapter 33 Quiz

Question 1

1. What groups provide the various atoms in a purine molecule?

Answer 1

Carbon dioxide, aspartate, glutamine, glycine and tetrahydrofolate

Question 2

1. What drugs block purine nucleotide biosynthesis?

Answer 2

Antifolate dugs and glutamine analogs

Question 3

1. What nucleotides can be synthesized from IMP?

Answer 3

Guanine and Adenine

Question 4

1. What amino acids are required for their synthesis from IMP?

Answer 4

Glutamine to have it converted to guanine and Aspartate to convert it to Adenine

Question 5

1. Why is hepatic purine biosynthesis stringently regulated?

Answer 5

it is energetically expensive; ATP, glycine , glutamine, partake and reduced tetrahydrofolate is all consumed; it is thus necessary to closely regulate purine biosynthesis.

Question 6

1. How is AMP and GMP biosynthesis from IMP regulated?

Answer 6

feedback system

Question 7

1. What molecules including amino acids are required for the biosynthesis of pyrimidine nucleotides?

Answer 7

Carbamoyl Phosphate and Aspartate

Question 8

1. Human catabolize purines to what molecule?

Answer 8

Uric Acid

Question 9

1. Starting with Adenosine, what is the first reaction in metabolism of adenosine? What is the name of the molecule?

Answer 9

Oxidation the amino group is replaced with an Oxo group. INOSINE

Question 10

1. What is the second reaction in the metabolism of adenosine? What is the name of this molecule?

Answer 10

The hydration of the sugar from the Adenosine base is now called HYPOXANTHINE

Question 11

1. What is the 3rd reaction in the metabolism of adenosine? What is the name of the molecule?

Answer 11

Another oxidation at carbon number #2. Xanthine.

Question 12

1. What is the action of or role of Xanthine Oxidase?

Answer 12

to oxidize the xanthine molecule at the number 8 carbon to uric acid

Question 13

1. What are the disorders of purine catabolism? Know the name as well as the enzyme that is deficient.

Answer 13

Gout - PRPP synthase (increasing ribose affinity and resistance to feedback inhibition)
Lesch-Nyhan Syndrome - Hypoxanthine-guanine phosphoribosyl transferase
von Gierke - glucose-6-phosphatase
Hypouricemia - xanthine oxidase
Adenosine Deaminase Deficiency
Nucleoside Phosphorylase Deficiency

Question 14

1. What is the name of the final metabolic product of Cytosine and Uracil?

Answer 14

Beta-Alanine

Question 15

1. What is the name of the final metabolic product of Thymine?

Answer 15

Beta-AminoButyrate

Question 16

1. What is orotic aciduria and what enzyme is it caused by?

Answer 16

types and is basically the inability of mitochondria being able to utilize carbamoyl phosphate, this then leads to the overproduction of Orotic Acid
Type I has the absence of both orotate phosphoribosyl transferase and orotidylate decarboxylase
Type II is due to the absence of orotidylate decarboxylase only