Where are we going with this? The information on this page should increase understanding related to this standard: Model and understand aerobic respiration demonstrating the flow of matter and energy out of a cell and explain energy transfer systems. Also, compare aerobic respiration to alternative processes of glucose metabolism.
So, how many names does this thing have?
"The electron transport chain (ETC; respiratory chain) is a series of protein complexes that transfer electrons from electron donors to electron acceptors via redox reactions (both reduction and oxidation occurring simultaneously) and couples this electron transfer with the transfer of protons (H+ ions) across a membrane. The electron transport chain is built up of peptides, enzymes, and other molecules…" (Source, 2021-11).
Let's try to get a handle on that. So…
- It receives electron carriers from the Krebs cycle and uses them, along with oxygen (hence it is aerobic), to create ATP which is passed on to the cell to provide energy for cellular functioning.
- The process takes place in the inner membrane of the mitochondria.
- It produces water as a byproduct.
The ETC is the final step of cellular respiration. We further discussed that it occurs in the mitochondria and that it is aerobic.
- Each NADH can produce 3 ATP.
- Each FADH2 can produce 2 ATP.
- Electrons are brought to the ETC by NADH and FADH2.
- When electrons are dropped off, the Hydrogen that they are attached to is dropped off too.
- Therefore, when electrons are dropped off, NADH becomes NAD+ and FADH2 becomes FAD.
In other words, oxygen is the final electron acceptor.
- About 36-38 total ATP are made in cellular respiration.
- Remember, 2 ATP were used in glycolysis.
- The net gain of ATP in cellular respiration is 34-36 ATP.
- Glycolysis: 2 ATP (anaerobic)
- Citric Acid Cycle + ETC: ~34 ATP (aerobic)