D. Major Metabolic Pathways - Synthesis and Degredation of Macromolecules (nucleotides)

Question 0

Nitrogenous bases are derived from either ….. or …..

Answer 0

Purine or pyrimidine.

Question 1

Define nucleotide. What is the difference between ribonucleotide and deoxynucleotide. What is a nucleoside?

Answer 1

a phosphate ester of pentoses in which a nitrogenous base is linked to a C(1’) of the sugar residue.

A nucleoside is when the phosphate group is absent.

Question 2

Purine and Pyrimidine derive mainly which nucleic acids?

Answer 2

purine components are - adenine and guanine

Pyrimidine residues are - cytosine, uracil and thymine.

Question 3

Synthesis of purine ribonucleotides.
Synthesis of Inosine Monophosphate.

a-D Ribose-5-phosphate + ATP –> ? (enzyme?)

Answer 3

a-D-Phosphoribosyl a- pyrophosphate (PRPP)

ribose phosphate pyrophosphokinase.

Question 4

Synthesis of purine ribonucleotides.
Synthesis of Inosine Monophosphate.

a-D-Phosphoribosyl a- pyrophosphate (PRPP) + ??? –>? and enzyme

Answer 4

Glutamine

enzyme is amidophosphoribosyl

amidophosphoribosyl transferase + glutamate