Question

An amphibolic pathway is
A. TCA cycle
B. Calvin cycle
C. Terminal oxidation
D. Electron transport chain

Answer 1

Hint: Amphibolic pathway is a biochemical pathway that involves both Catabolic and anabolic pathways. Catabolism means nothing but the degradative pathway, which means large and complex molecules are degraded into small simple molecules, while the anabolic pathway means a reconstructive pathway where the simple and basic molecules combine to form the large complex molecules.

Complete answer:
One example of the amphibolic pathway is the TCA cycle, and it is also called Krebs cycle, and citric acid cycle, because citrates are formed in reactions.
This cycle takes place in the mitochondria and the enzymes required for this pathway are present in the mitochondrial matrix.
This Cycle utilizes 2/3rd of the oxygen consumed by the body.
And about 65 to 70% of ATP was synthesized in the Krebs cycle.
There are both reversible and irreversible reactions that occur in the cycle.
The cycle starts with the 2 molecules of Acetyl CoA, where it is the product of pyruvate, which is formed in the link reaction that occurred after glycolysis.
The acetyl CoA undergoes various reactions, where there are a total of 8 steps present and it is a cyclic pathway.
Finally, there is the formation of Oxaloacetate, and this product plays a catalytic role in this citric acid cycle.
It is one of the aerobic respiration pathways where out 38 molecules of ATP, 60% which means 20 molecules are formed in the citric acid cycle and some are formed in the link reaction.

So as both catabolic and anabolic reactions have occurred in this pathway, this is called an Amphibolic pathway. And the answer is the TCA cycle.

Note: Examples of catabolic reactions break down of proteins into amino acids, and fats into fatty acids, and carbohydrates into monosaccharides, and at the same time, the smaller molecules are biosynthesized to larger and complex molecules then it is anabolic, and other examples of this amphibolic pathway are Embedon Mayer off-pathway, and Pentose phosphate pathway.