Definition of Krebs Cycle

The chemical reactions that occur in the breathing of aerobic cells are subject to a process of molecular transformation. This process is known as the Krebs cycle or as the citric acid cycle. It is a metabolic pathway in which a series of chemical reactions occur consecutively.

A complex process at the cellular level

The transformation process at the molecular level takes place in the mitochondria of aerobic cells, that is, those that have the presence of oxygen.

When glucose enters the cell it goes through a process called glycolysis. It is from this moment on that the Krebs cycle properly begins. In a first stage, glucose is transformed into pyruvate (this organic compound is decisive in the metabolism), which in turn is converted to acetyl coenzyme (the enzyme that transforms pyruvate into acetyl coenzyme is pyruvate dehydrogenase).

In this process of molecular change, dehydrogenase uses a series of substances: thiamine or vitamin B1, vitamin B2 or FAD, vitamin B3 or NAD, vitamin B5 and lipoic acid.

Once the acetyl coenzyme is formed a new molecule to form citrate. In a next phase, alpha ketoglutarate is formed from the intervention of an enzyme, isocitrate. Alpha ketoglutarate reuses the same five substances used in the pyruvate phase.

All these reactions allow the elimination of Co2 and this makes the cells of a living organism able to carry out the function of respiration. In this sense, the Krebs cycle helps us understand the concept of metabolism.

All systems of the human body have metabolic activity

In this sense, the cells of the body exchange matter and Energy to maintain, repair or reproduce cellular structures. This process of molecular transformation is known as metabolism.

The metabolism is divided into two phases: anabolism Y catabolism. In the first, the cells of the body obtain micronutrients that join and create macronutrients (protein, carbohydrates and fats). In catabolism there is a process of destruction where the body breaks down the different macronutrients into simpler molecules.

The role of glucose

Regardless of the complexity of the molecular processes that occur in the Krebs cycle, this process can be understood as what allows us to perform vital functions that require a certain energy, such as walking, running or to work.

It is worth remembering that this process begins precisely with the action of glucose, which comes from fruits, honey and the starch found in rice, pasta or potatoes. If a person ingests a high amount of glucose and does not do enough physical exercise, it is very likely that cholesterol will appear in the blood.

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