Nucleotide Synthesis and Pathways Chapter 23

These flashcards cover key concepts from the lecture notes on nucleotide synthesis, including pathways, enzyme functions, and important metabolic ratios.

What are the two major types of bases in nucleotide synthesis?

Purines (Adenine, Guanine) and Pyrimidines (Cytosine, Thymine or Uracil)

Which pathway is responsible for the synthesis of NADPH?

The Pentose Phosphate Pathway synthesizes NADPH.

What is the main sugar component in nucleotides?

The main sugar components in nucleotides are deoxyribose (in DNA) and ribose (in RNA).

What is the role of Ribonucleotide Reductase?

Ribonucleotide Reductase converts ribonucleotides to deoxyribonucleotides.

Which enzyme is primarily responsible for the first step of Purine Synthesis?

Ribose phosphate pyrophosphokinase initiates purine synthesis.

What is the final product of the purine synthesis pathway?

Inosine monophosphate (IMP) is the final product of the purine synthesis pathway.

What is the substrate for the enzyme Carbamoyl Phosphate Synthetase II in pyrimidine synthesis?

The substrate is HCO3 and Glutamine.

What are the key differences between purine and pyrimidine synthesis?

Purine synthesis builds the base onto ribose, while pyrimidine synthesis builds the base separately and then adds it to ribose.

What is the significance of NADP+ and NADPH ratio in cellular metabolism?

Cells maintain a ratio of NAD+ / NADH = 1000 but NADP+ / NADPH = 0.01 to support various metabolic functions.

What condition can result from excess uric acid production?

Excess uric acid can lead to gout, a painful arthritic condition.

What are the substrates for the salvage pathway of purines?

Adenine, Guanine, and Hypoxanthine are substrates that can be recycled in the salvage pathway.