The Three Major Steps in Cellular Respiration

Glycolysis takes place in the cytoplasm, in aseries of reaction, glucose is broken down into pyruvate. Energy released and trapped in two molecules of ATP. Pyruvate moves into the mitochondrion.

The second major reaction of respiration is called the Krebs Cycle. It is named after the scientist discovered the different steps in the cycle. The Krebs cycle takes place in the liquid part of the mitochondrion here, acetyl coenzyme A (acetyl CoA) w/c is formed from pyruvate enters the cycle. Sveral substances are formed w/c are used again. But three products move out of the cycle. These are carbon dioxide w/c leaves cell, two molecules of ATP, and the hydrogen carrier, AH2.

AH2 passes into the cristae where the third major reaction occurs. AH2 break down into hydrogen and electrons (e). The electrons flow from one electron acceptor to another. As the electrons flow, energy is released forming a total of 32 ATP molecules. The last electron acceptor is oxygen w/c finally forms water with hydrogen.

The simple disscusion illustrates the gradual breaking down of the glucose molecule. Energy is slowly released and captured in ATP. For every molecule of glucose, a total number of 36 ATP molecules are formed.