Aerobic cellular respiration

Cellular respiration is an energy-producing process that uses glucose to produce adenosine triphosphate or ATP, an organic compound the body can use for energy.

Aerobic cellular respiration occurs in the presence of oxygen and can be divided into three main phases: glycolysis, the Krebs cycle (sometimes known as the tricarboxylic acid/TCA cycle, or citric acid cycle), and the electron transport chain. During these phases, glucose, a simple sugar, is broken down to release energy in the form of ATP. ATP is produced during all three phases, and the maximum yield for aerobic respiration is 38 ATP.

The by-products of this process, CO2 and H2O, carbon dioxide and water leave the body via respiration, urination, and perspiration.

The general equation for the cellular respiration process is:

Glucose (C6H12O6) + 6 O2 + 38 ADP → 6 CO2 + 6 H2O + 38 ATP + heat One molecule of Glucose, 6 molecules of oxygen and 38 molecules of A D P react to form six molecules of carbon dioxide, six molecules of water, 38 molecules of A T P, and heat.

Steps in aerobic cellular respiration. Within a cell, carbohydrates are broken down to glucose. Glucose undergoes glycolysis to produce pyruvate, which enters the mitochondria. In the presence of oxygen, aerobic respiration proceeds. The pyruvate becomes acetyl Co A and enters the Krebs cycle. Krebs cycle products carry over to the electron transport chain, where oxygen is the final electron receptor. NADH produced during glycolysis also enters the electron transport chain.

Figure: Overview of the aerobic cellular respiration process.