Which of the following urea cycle intermediate is the link between urea cycle and TCA cycle?
Ans. b) Fumarate is the link between urea cycle and TCA cycle Urea Bicycle = Urea cycle + TCA cycle Both are independent cycles but are linked. 1 nitrogen in the urea is obtained from the aspaate obtained by transamination of oxaloacetate produced in TCA cycle (See fig) The fumarate that is produced in urea cycle can be used as an intermediate in the citric acid cycle.
Argininosuccinate
Fumarate
Oxaloacetate
Succinate
TCA Cycle