L7 - De Novo Synthesis Of Purine Nucleotides

Question 1

What is the starting point of de novo synthesis of purine nucelotides?

Answer 1

Sugar phosphate which is phosphorylated
Then the puring ring is assembled on the ribose ring

Question 2

What is the commited step?

Answer 2

Conversion of PRPP to 5-phosphoribosylamine

C-1 configuration is inverted from alpha to beta
= glycosidic bond seen in narutally occuring nucleotides

Question 3

What happens after the c1 is converted from a to b?

Answer 3

First ring is built of the ribose

Question 4

How is the second ring built?

Answer 4

Using the first ring
Using ATP

Question 5

What is the common precursor? What can it create?

Answer 5

Inosine 5’-phosphate

AMP and GMP

Question 6

What is the benefit of using a common precursor?

Answer 6

Synthesis is very efficient (energy, enzymes)