What is the ATP energy yield associated with each of the following?
a. FADH₂ → FAD

Verified step by step guidance

1. Understand the context: ATP energy yield refers to the amount of ATP generated during the electron transport chain when molecules like FADH₂ or NADH donate electrons.
2. Recall that FADH₂ is a coenzyme that donates electrons to the electron transport chain at Complex II, bypassing Complex I. This results in fewer protons being pumped across the mitochondrial membrane compared to NADH.
3. Note that the energy yield of FADH₂ is typically associated with the production of approximately 1.5 ATP molecules per molecule of FADH₂. This is due to the lower number of protons pumped and the subsequent ATP synthesis via ATP synthase.
4. Write the chemical reaction for the oxidation of FADH₂: ${\mathrm{FADH}2}_{\to }+{H2}_O$. This represents the donation of electrons to the electron transport chain.
5. Understand that the energy yield is an approximation and can vary slightly depending on the efficiency of the electron transport chain and ATP synthase in specific cells or organisms.

Key Concepts

ATP Yield from FADH₂

FADH₂ is a reduced coenzyme that plays a crucial role in cellular respiration, particularly in the electron transport chain. When FADH₂ is oxidized to FAD, it donates electrons, contributing to the generation of ATP. The typical ATP yield from one molecule of FADH₂ is approximately 1.5 ATP, as it enters the electron transport chain at a lower energy level than NADH.

Electron Transport Chain (ETC)

The electron transport chain is a series of protein complexes located in the inner mitochondrial membrane that facilitate the transfer of electrons from electron donors like NADH and FADH₂ to electron acceptors. This process creates a proton gradient across the membrane, which is used by ATP synthase to produce ATP. Understanding the ETC is essential for calculating the ATP yield from various substrates.

Oxidative Phosphorylation

Oxidative phosphorylation is the metabolic pathway through which cells generate ATP using energy derived from the oxidation of nutrients. It involves the transfer of electrons through the ETC and the subsequent phosphorylation of ADP to ATP via ATP synthase. This process is critical for understanding how energy is produced in aerobic respiration and the specific contributions of different electron carriers like FADH₂.