Are all of these statements correct about the electron transport chain in humans?
Each FADH2 yeields 2 ATP, each NADH yields 3 ATP, and the final electron acceptor is oxygen.
Yes, all of these statements are correct about the electron transport chain in humans. To understand why, let's dive into the electron transport chain and how it generates ATP.
The electron transport chain is a series of protein complexes located in the inner mitochondrial membrane in humans. It plays a crucial role in the process of cellular respiration, specifically oxidative phosphorylation, which generates the majority of ATP in cells.
1. Each FADH2 yields 2 ATP: During cellular respiration, FADH2, which is a product of the Krebs cycle (also known as the citric acid cycle), donates its electrons to the electron transport chain. These electrons pass through several protein complexes, ultimately leading to the pumping of protons (H+) across the inner mitochondrial membrane. The energy derived from this electron flow is harnessed to create an electrochemical gradient of protons, which then drives the synthesis of ATP. In the case of FADH2, each molecule donates its electrons at a later stage of the electron transport chain, resulting in a lower number of protons being pumped. This leads to the production of 2 ATP molecules.
2. Each NADH yields 3 ATP: Similarly, NADH, also produced during the Krebs cycle, donates its electrons to the electron transport chain. The electrons are transported through the protein complexes, causing protons to be pumped across the inner mitochondrial membrane. This proton gradient is then used to generate ATP. In comparison to FADH2, NADH donates its electrons earlier in the electron transport chain, resulting in a higher number of protons being pumped. Consequently, each NADH molecule leads to the production of 3 ATP molecules.
3. The final electron acceptor is oxygen: As the electrons are transported along the electron transport chain, they pass through several protein complexes and carriers. Ultimately, the electrons combine with molecular oxygen (O2), which serves as the final electron acceptor. This union of electrons and oxygen leads to the formation of water (H2O). Thus, the presence of oxygen is crucial for the electron transport chain to function effectively.
In summary, each FADH2 molecule yields 2 ATP, each NADH molecule yields 3 ATP, and oxygen serves as the final electron acceptor in the electron transport chain of humans.