Nucleotide Synthesis

Question 1

What do nucleotides contain?

Answer 1

A nitrogen base, a sugar and a phosphate

Question 2

What is the difference between purines and pyrimidines?

Answer 2

Purines have 2 rings and pyrimidines have 1 ring

Question 3

What occurs in purine nucleotide synthesis?

Answer 3

A ribose-5-P from (PPP) is phosphorylation into activated pentose

Question 4

What happens in pyrimidine nucleotide synthesis?

Answer 4

Carbamoyl phosphate is synthesised from glutamine by carbamoyl-P-synthetase II. Carbamoyl phosphate reacts with aspartate producing carbamoyl aspartate

Question 5

What are the general roles of nucleotides in metabolism? (3)

Answer 5

They form DNA and RNA, they are essential to energy conversions and they form secondary messengers (cAMP, cGMP)

Question 6

Which nucleotides are purines? (2)

Answer 6

Alanine and Guanine

Question 7

Which nucleotides are pyrimidines? (3)

Answer 7

Thymine, uracil and cytosine

Question 8

What are the precursors to purines and pyrimidines? (2)

Answer 8

Amino acids and products of the PPP