proteins in the electron transport chain are located in enzymes.
proteins in the electron transport chain are located in enzymes.
where are proteins in the electron transport chain located?
enzymes
oxidative phosphorylation works by using energy-releasing chemical reactions to drive energy-requiring reactions: the two sets of reactions are said to be "coupled". this means one cannot occur without the other. the flow of electrons through the electron transport chain, from electron donors such as nadh to electron acceptors such as oxygen, is an exergonic process – it releases energy, whereas the synthesis of atp is an endergonic process, which requires an input of energy. both the electron transport chain and the atp synthase are embedded in a membrane, and energy is transferred from electron transport chain to the atp synthase by movements of protons across this membrane, in a process called "chemiosmosis". in practice, this is like a simple electric circuit, with a current of protons being driven from the negative n-side of the membrane to the positive p-side by the proton-pumping enzymes of the electron transport chain. these enzymes are like a battery, as they perform work to drive current through the circuit. the movement of protons creates an electrochemical gradient across the membrane, which is often called the "proton-motive force". it has two components: a difference in proton concentration (a h gradient, δph) and a difference in electric potential, with the n-side having a negative charge.
oxidative phosphorylation
the last process in aerobic respiration is oxidative phosphorylation, also known as the electron transport chain. here nadh and fadh, which contain the energy in the form of electrons, deliver their electrons to the inner membranes of the mitochondrion to power the production of atp. oxidative phosphorylation contributes the majority of the atp produced, compared to glycolysis and the krebs cycle. while the atp count is glycolysis and the krebs cycle is two atp molecules, the electron transport chain contributes, at most, twenty-eight atp molecules. a contributing factor is due to the energy potentials of nadh and fadh. as they are brought from the initial process, glycolysis, to the electron transport chain, the energy stored in them are now utilized. a second contributing factor is that cristae, the inner membranes of mitochondria, increase the surface area and therefore the amount of proteins in the membrane that assist in the synthesis of atp. along the electron transport chain, there are separate compartments, each with their own concentration gradient of h + ions, which are the power source of atp synthesis. to convert adp to atp, energy must be provided. that energy is provided by the h+ gradient. on one side of the membrane compartment, there is a high concentration of h+ ions compared to the other. the shuttling of h+ to one side of the membrane is driven by the exergonic flow of electrons throughout the membrane. these electrons are supplied by nadh and fadh as they transfer their potential energy. once the h+ concentration gradient is established, a proton-motive force is established, which provides the energy to convert adp to atp. the h+ ions that were initially forced to one side of the mitochondrion membrane now naturally flow through a membrane protein called atp synthase, a protein that converts adp to atp with the help of h+ ions.
carbohydrate catabolism