Why is the electron transport chain (ETC) often considered the 'Super Bowl' of aerobic respiration?

• A. Because it occurs in the cytoplasm of the cell.
• B. Because it is the first step where glucose is broken down.
• C. Because it directly converts pyruvate into carbon dioxide.
• D. Because it produces the majority of ATP during cellular respiration.

Answer: (D)

Verified step by step guidance

1. Understand the context of aerobic respiration: Aerobic respiration is a process where cells generate energy (ATP) by breaking down glucose in the presence of oxygen. It consists of several stages, including glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain (ETC).
2. Recognize the role of the electron transport chain (ETC): The ETC is the final stage of aerobic respiration, located in the inner mitochondrial membrane. It is responsible for producing the majority of ATP through oxidative phosphorylation.
3. Explain how the ETC works: Electrons are transferred through a series of protein complexes and carriers in the mitochondrial membrane. These electron transfers create a proton gradient across the membrane by pumping protons (H⁺) into the intermembrane space.
4. Describe ATP synthesis: The proton gradient drives protons back into the mitochondrial matrix through ATP synthase, a protein complex that synthesizes ATP from ADP and inorganic phosphate (Pi). This process is called chemiosmosis.
5. Clarify why the ETC is considered the 'Super Bowl' of aerobic respiration: The ETC produces the majority of ATP during cellular respiration, making it the most energetically significant step. This is why it is often referred to as the 'Super Bowl' of aerobic respiration.