<prompt> Krebs cycle and urea cycle are linked by-SuccinateMalatea ketoglutarateFumarate  <response>: Ans. is d i.e., Fumarate Fumarate is released during urea cycle, which is an intermediate of Krebs cycle, thus linking the two.Points to remember about urea cycle1. Urea cycle happens is a pathway active only in liver.2. It is partly mitochondrial, partly cytoplasmic.3. CPS I is the rate limiting enzyme of urea cycle and CPSI is stimulated by NAG N Acetyl Glutamate Please note CPS II is an enzyme of pyrimidine synthesis.4. Net ATP used for detoxifying 1 molecule of ammonia is 1.55. N1 donor of urea is ammonia and N2 donor is aspartate.6. Arginase is the step where in urea is released. 