$\beta$-oxidation occurs in .........

Respiratory pathway is believed to be a catabolic pathway. However,the nature of the $TCA$ cycle is amphibolic. Explain.

Given below are two statements:
Statement $I$ - $A$ stepwise release of chemical bond energy facilitates the utilization of a relatively higher proportion of that energy in $ATP$ synthesis.
Statement $II$ - Due to stepwise oxidation of respiratory substrate,the same pathway may be used for synthesis of another biomolecule.
In light of above statements,select the correct answer from the options given below.

$A$ : Fat breakdown yields fatty acids and glycerol.
$R$ : Glycerol enters glycolysis through serine formation.

Give scientific reasons:
$(1)$ Krebs' cycle is an important process.
$(2)$ Sometimes an amphibolic pathway is seen in respiration.

The maximum amount of energy / $ATP$ is released during the oxidation of which of the following?