$A$ vitamin which plays a metabolic role in the conversion of pyruvic acid into acetyl $CoA$ is

The enzymes for cellular respiration are located in:

The connecting link between glycolysis and the Krebs cycle is ...... .

$FADH_2$ is produced during which of the following reactions?

$A -$ The $TCA$ cycle starts with the condensation of Acetyl group with $OAA$ and water to yield citric acid.
$R -$ Kreb's cycle occurs in the cytoplasm of the cell.

Describe the Krebs cycle.