Question

Conversation of ammonia into uric acid occurs through
A. Ornithine cycle
B. Guanine cycle
C. Inosinic pathway
D. Krebs cycle

Answer 1

Hint: Uric acid is a purine-like compound found in nucleic acids. Uric acid production involves a complex metabolic pathway that consumes a lot of energy compared to processing other nitrogenous wastes such as urea. However, it has the advantage of reducing water loss and thus water consumption.

Complete answer:
Ornithine cycle- Ornithine cycle or urea cycle also known as kreb-henseleit cycle. It occurs in the liver. The urea cycle (also known as the ornithine cycle) is a biochemical reaction cycle in which ammonia is converted to urea. The urea cycle converts the highly toxic ammonia into urea for excretion.
Guanine cycle-After nucleotides are synthesized; they can exchange phosphate into mono-, di-, and triphosphate molecules. The conversion of nucleoside diphosphate (NDP) to nucleoside triphosphate (NTP) is catalysed by nucleoside diphosphate kinase, which uses ATP as a phosphate donor. Likewise, nucleoside monophosphate kinases carry out phosphorylation of nucleoside monophosphates. Adenylate kinase is a specific nucleoside monophosphate kinase that only acts on adenosine monophosphate. So this option is not correct.
Inosinic pathway -The inosine pathway is an important step in metabolism. When uric acid is made from ammonia in the liver, it is known as the inosine pathway. The breakdown of purines produces uric acid. When purines are broken down, Ionosinic acid is formed.
Krebs cycle or Krebs cycle-The TCA cycle (after that H. A. Krebs) is a sequence of reaction cycles in which pyruvic acid produced in EMP and EDP is oxidized. The cycle acts on aerobic organisms, including animals, plants, and microorganisms. The main function of this cycle is to produce energy through the oxidation of acetic acid, which is obtained by decarboxylation of pyruvic acid and introduced into the TCA cycle as acetyl-CoA. In this sense, cycles are a consequence of catabolic reactions. The TCA cycle also produces several intermediate products which are used for the biosynthesis of proteins, nucleic acids, etc. Thus the cycle has a dual purpose, on the one hand a catabolic role and on the other an anabolic role. Such dual target metabolic pathways are known as amphibolies.
So, the correct answer is “Option A”.

Note:
Uric acid is also a lesser toxic form than ammonia and urea. It contains four nitrogen atoms; Only a small amount of water is needed for separation. The solute precipitates and forms crystals. Xanthine oxidase enzymes produce uric acid from xanthine and hypoxanthine, which are then produced by other purines. Xanthine oxidase is a large enzyme whose active centre consists of the metal molybdenum, which is bound to sulphur and oxygen. Uric acid is released in a hypoxic state.