Functions of the Respiratory Chain

Cellular respiration is the function by which a cell obtains energy to carry out its functions, through the splitting of food substances into energy molecules more simple. The unfolding is the chemical reaction by which a molecule, due to the presence of other substances, called catalysts, is transformed into another, simpler one.

To carry out its functions, the cell obtains energy from a molecule called adenosine triphosphate. Adenosine triphosphate is made up of three phosphate molecules, attached to a monosaccharide (simple sugar) called ribose. When this molecule is hydrolyzed (hydrogen is added), it breaks and releases one of the phostates, releasing water and energy among others.

Cellular respiration consists of the series of cellular reactions that take place from the entry of glucose to its conversion into ATP.

Breathing chain example:

Glycolysis At the beginning of the breathing process. Glucose crosses the cell membrane and in the cytoplasm the glucose molecule undergoes an oxidation process, dividing into two molecules of pyruvic acid, also called pyruvate. Other substances, such as amino acids, are also oxidized, releasing amines and pyruvate.

Decarboxylation. Pyruvate molecules enter the mitochondria, where they begin to be attacked by enzymes that cause oxidative decarboxylation. At first an enzyme is responsible for releasing one of the carbons of pyruvic acid (releasing CO2), and at the same time another The enzyme is responsible for releasing two hydrogen atoms, producing an Acetyl radical (acetic acid without hydroxyl radical -OH).

Krebs cycle. Acetyl radicals are transported by another enzyme, called “Coenzyme A”, towards the matrix mitochondrial (the nucleus of the mitochondria), where acetyl radicals are oxidized and released Energy. In this phase, the CO2 molecules are also recombined with coenzyme A to produce a total of 6 oxidized acetyl molecules, which form the coenzymes NADH and FADH2.

In the next step, the resulting coenzymes, called NADH and FADH2, are oxidized again, so that they have eletronegativity and can accept electrons and protons, which are provided by other coenzymes, which add electrons and phosphorylate (add phosphorus) to the coenzymes, until adding three phosphorus molecules and oxygen molecules, to produce ATP