Amphibolic Pathway General Overview – Imaluop

Hi, today we will discuss a special type of metabolic reaction amphibolic pathway general overview and examples of amphibolic pathways in our living systems. Daily a large number of biochemical reactions or pathways occurs in our living cells to maintain the cellular activity of the living cells.  

Some of them involve building up new biochemicals while some of them involve breaking down from compound biomolecules to simple biomolecules. Some of them are required for production or synthesis of essential biochemicals like enzymes while some of them are necessary to release energy to run the cellular activity continuously.  

Now come to the point the two major types of metabolic reaction we know are anabolic metabolic reaction and catabolic metabolic reaction.

Nature of catabolic and anabolic metabolism is opposite because anabolic reactions involve producing new complex compounds from simple molecules while catabolism refers to the breakdown of complex molecules into simple molecules.  

Anabolic reaction occurs in cells where there is a requirement for any biochemical for cells and increases the dry weight of the cells but catabolism causes break down of molecules especially during break down of food molecules during digestion.

For example when our cell requires protein which synthesises in cells using simple amino acids monomer is an example of anabolism. 

What is Anabolic Pathway: 

In our cells sometimes some pathway or reaction occurs which involves both the type of cellular metabolic reaction anabolism and catabolism which is referred as amphibolic pathway mean both catabolism and anabolism.

So here building up new molecules or anabolism and break down of complex molecules or catabolism both occurs in our cells together. To understand the amphibolic pathway we need to study an example which will show how amphibolic pathways operate in our living cells.

For this reason we should notice reaction occurs in a phase of respiration, Krebs cycle in which both anabolism and catabolism occurs. 

Krebs Cycle as Example of Amphibolic Pathway: 

In cellular respiration glucose breakdown releases the energy in the food in the form of ATP which is a catholic reaction but only glucose not used for cellular metabolic energy.

Lipid and fat also utilised for release the metabolic energy when cells require more energy. But they do not participate in respiration directly instead they undergo various biochemical reactions to convert into simple molecule then they can be used to release energy. 

Fat breaks down into fatty acid and glycerol during digestion and protein break down into its monomer amino acids during the process of digestion. Then the fatty acids converted into acetyl co A and the glycerol convert into 3 – phosphoglyceraldehyde while some amino acids convert into pyruvate and other amino acids convert into acetyl CoA.

These simpler forms of fat and protein can enter the Krebs cycle but have you noticed that all this process is catabolism because here complex compounds break down into simpler forms.  

So break down of fat and protein and participate in respiration is an example of catabolic pathway but respiration does not always break down molecules something it involves production of molecules which is anabolic pathway and for this reason respiration is an example of amphibolic pathway.  

We notice anabolic pathway in respiration when our cells do not need very much energy but need protein and fat for various reasons. During the requirements of fat and protein respiration pathway halt and the produced acetyl CoA again converts back to fatty acids to meet the cell requirements.  

So we can say that Krebs cycle or Tricarboxylic Acid cycle or TCA is a very clear example of an amphibolic pathway when both anabolism and catabolism occur in our cells. 

Reference: Amphibolic Pathway General Overview

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