Ammonia causes depletion of which of the following in TCA cycle?
In Hyperammonemia (i.e. excess amino groups in cells), a large amount of alpha keto glutarate (intermediate of TCA) combine with an excess of ammonia in cells to form glutamate which fuher give rise to glutamine by taking up more ammonia (see fig). This leads to depletion of alpha-KG. As alpha-KG is an intermediate of TCA cycle, so TCA cycle stops and the brain is affected as brain is highly dependent on this aerobic pathway for energy. So in case of hyper ammonia alpha-ketoglutarate & glutamate will decrease and glutamine will increase.
Oxaloacetate
Alpha-Keto glutarate
Fumarate
Malate
NEET 2019