Question

In Kreb’s cycle and Urea cycle the linking amino acid is:

• A. Fumarate
• B. Arginine
• C. Arginine
• D. Aspartate

Answer 1

The Correct Option is D

The linking amino acid in Kreb’s cycle and Urea cycle is Aspartate. Here's why:

• In the Kreb's cycle, which is also known as the citric acid cycle, various intermediates are generated and some are part of other metabolic pathways. Aspartate is formed by the transamination of oxaloacetate, a Kreb's cycle intermediate.
• The Urea cycle involves the incorporation of nitrogen into urea for excretion. Aspartate directly contributes its nitrogen to form urea in this cycle.

The integration of these two cycles through Aspartate is crucial for nitrogen metabolism within the cell.