Which of the following is a $2C$ intermediate compound formed in the respiratory breakdown reaction of fats and carbohydrates?

Where does glycerol enter the respiratory pathway?

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

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

Given below are two statements:
Statement $I$ - Reactions involved in Krebs cycle are anabolic and catabolic.
Statement $II$ - During oxidation of acetyl $CoA$,stepwise oxidation of the acetyl part of acetyl $CoA$ occurs.
In light of the above statements,choose the most appropriate answer from the options given below.

Where is $NADP^+$ reduced to $NADPH$?