What Are the Coupled Stages of Cellular Respiration?

Cellular respiration's coupled reaction begins with adenosine triphosphate, an enzyme that works with other chemicals in the cell to break down glucose into usable energy. The cell uses some initial ATP to get back more ATP at the end of the coupled cycle.

First, ATP breaks down the carbon glucose into pyruvic acids. The pyruvic acids couple with the adenosine in ATP, which is a co-enzyme designated for this purpose. When this coupling occurs, it releases some carbon dioxide.

The next step is the Krebs cycle, which happens inside the mitochondria of the cell. The carbon dioxide binds with an oxalacetate carbon molecule in the mitochondria. This causes the carbon to break down and release more energy, electrons and carbon dioxide. The oxalacetate is replenished at the end so that it can bind with more carbon molecules.

The next stage involves oxidative phosphoration, in which the electrons from the Krebs stage move around the mitochondria and force positive ions to leave the membrane. A chemiosmosis occurs at this point because the ions that were forced out go back through the membrane and generate more ATP energy through these movements.

At the end of the cycle, the mitochondria has created more ATP than what was present at the start in addition to some carbon dioxide and water molecules.