Hii!
TCA cycle is known as Tri Carboxylic Acid cycle and is also known as Kreb's cycle after the name of the scientist who found it. So, the only 5 carbon compound, formed during this cycle is "Ketoglutaric acid." In this cycle, oxalosuccinic acid gets decarboxylated in presence of enzyme decarboxylase and forms 5 carbon Ketoglutaric acid.
Hope this helps.
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