Optometry Admission Test (OAT) Practice

What is produced through the complete oxidation of glucose during cellular respiration?

1. Oxygen

2. C6H12O6

3. ATP

4. Water

The correct answer is: ATP

During cellular respiration, glucose (C6H12O6) undergoes a series of chemical reactions that result in the complete oxidation of the molecule. This process occurs in three main stages: glycolysis, the citric acid cycle, and oxidative phosphorylation. The primary purpose of cellular respiration is to convert the energy stored in glucose into ATP (adenosine triphosphate), which is the main energy currency used by cells. As glucose is oxidized, electrons are transferred to electron carriers such as NADH and FADH2, which then feed into the electron transport chain. In this chain, the energy from these electrons is used to pump protons across the mitochondrial membrane, creating a proton gradient. As protons flow back through ATP synthase, ATP is produced. Additionally, during this process, byproducts such as carbon dioxide and water are generated. However, the primary product of this metabolic pathway is ATP, as it provides the necessary energy for various cellular functions. Therefore, recognizing ATP as the central product of glucose oxidation highlights the importance of cellular respiration in energy metabolism.