The electron transport chain is the final and most important step of cellular respiration. While Glycolysis and the Citric Acid Cycle make the necessary precursors, the electron transport chain is where a majority of the ATP is created. The Electron Transport Chain makes energy The simple facts you should know about the electron transport chain are: The process is a stepwise movement of electrons from high energy to low energy that makes the proton gradient The proton gradient powers ATP production NOT the flow of electrons This electron transport chain only occurs when oxygen is available.
In order to understand how the electron transport chain works, it is critical that you have a good understanding of what the mitochondria is and how it is organized. See figure 10 to help you review the structure of this important cell organelle.
Image derived from File: The Mitochondria is a double membrane organelle found within a cell. The Mitochondria have an inner and an outer membrane. The inner membrane folds in and out on itself and these folds are called Cristae. Cristae increase the total surface area of the inner membrane. The center of the mitochondrion is called the matrix and is analogous to the cytoplasm of a cell.
The Electron Transport Chain reactions take place on the inner membrane. The term, electron transport refers to the proteins on the inner membrane of the mitochondria that will take hydrogen atoms and electrons from NADH and FADH2 and then ultimately use the energy in the electrons to make ATP.
In the inner membrane of the mitochondrion is a series of protein complexes that will receive the electrons and pass them from one complex to another see figure NADH passes 2 high energy electrons onto a protein complex Complex I in the inner membrane of the mitochondria.
This complex is called NADH dehydrogenase.
NADH dehydrogenase does two things. First, it accepts a pair of high energy electrons from NADH second, it uses some of the energy from these electrons to undergo a conformational change.
Coenzyme Q is also called ubiquinone.
CoQ is a mobile shuttle that moves easily through the membrane and is able to relocate and react with Complex III. Cyt c another mobile shuttle that is a soluble protein on in the intermembranous space that moves easily along the membrane and reacts with Complex IV.
This is allowed to happen through another protein complex called ATP synthase. This process is called Oxidative Phosphorylation. The image above illustrates the Electron Transport Chain.
Oxygen is the final electron acceptor and becomes water. A quick recap of what has happened so far might go like this: Electrons and hydrogen ions were harvested from the C-H bonds of glucose.
These high energy electrons with hydrogen are carried from the reactions of glycolysis and the citric acid cycle to the electron transport chain on the inner membrane of the mitochondria. The electron transport chain takes these high energy electrons and gradually "uses" the energy to pump hydrogen ions to the intermembranous space.
As the energy in the electrons is used, the electrons don't have enough energy to form a C-H bond anymore, but they can form an O-H bond. Thus, oxygen comes along and accepts the electrons and hydrogen to form water. The cycle is complete and water can once again be used by a plant somewhere to participate in the photosynthetic reactions that will excite O-H bond electrons again.
The hydrogen ions that have been pumped into the intermembranous space are allowed to flow down their electrochemical gradient through ATP synthase. ATP is generated as a result and ATP is used to run the many molecular processes in our cells that keep us healthy and alive.
As energy is released in these many reactions of metabolism a little bit is lost as heat. Indeed, metabolism is responsible for a portion of our body heat. Glucose is not the only molecule with C-H bond energy to use in metabolic reactions.
Lipids and Proteins are also metabolized by our cells.All in all, the electron transport chain step by step explanation provided in this article should hopefully give you a better understanding of how this metabolic pathway works not only by itself, but also alongside the many other metabolic pathways as well.
Oxidative phosphorylation is made up of two closely connected components: the electron transport chain and chemiosmosis. In the electron transport chain, electrons are passed from one molecule to another, and energy released in these electron transfers is used to form an electrochemical gradient.
Understanding Electron Transport in Solar Wind This plasma affects the entire solar system, including Earth’s magnetic field and is therefore crucial to our understanding of space weather.
It is easiest to understand how electron transport works by dividing this process into three main events: In the electron transport chain, these electron carriers are oxidized, transferring their electrons to the carrier molecules embedded in the ETC membrane.
Understanding Electron Transport in Solar Wind This plasma affects the entire solar system, including Earth’s magnetic field and is therefore crucial to our understanding of space weather. Understanding metal doping for organic electron transport layers and not every metal works as an efﬁcient dopant.
Practical applicability is demonstrated by introducing doped transport layers in hole- and electron-transport layers. It was demonstrated that.