$TCA$ cycle is a

Which enzyme is required for the following conversion?
Pyruvic acid + $CoA + NAD^+ \longrightarrow$ Acetyl $CoA + CO_2 + NADH + H^+$

During the citric acid cycle,various organic acids undergo decarboxylation. Which of the following organic acids of the cycle have $4C$,$5C$,and $6C$ respectively?

Match the columns based on the number of carbon atoms in the compounds involved in the Krebs cycle:

Column-$I$	Column-$II$
$(a)$ $4$ $C$ compound	$(1)$ Acetyl $CoA$
$(b)$ $2$ $C$ compound	$(2)$ Pyruvate
$(c)$ $5$ $C$ compound	$(3)$ Citric acid
$(d)$ $3$ $C$ compound	$(4)$ $\alpha$-Ketoglutaric acid
	$(5)$ Malic acid

The $5-C$ compound formed during the $TCA$ cycle is:

All enzymes of the $TCA$ cycle are located in the mitochondrial matrix, except for one which is located in the inner mitochondrial membrane in eukaryotes and in the cytosol in prokaryotes. This enzyme is