How are protons pumped in the electron transport chain?

The electron transport chain is a series of proteins embedded in the inner mitochondrial membrane. Protons flow down their concentration gradient into the matrix through the membrane protein ATP synthase, causing it to spin (like a water wheel) and catalyze conversion of ADP to ATP.

Where are protons pumped in electron transport chain in photosynthesis?

The passing of the electron in the first part of the electron transport chain causes protons to be pumped from the stroma to the thylakoid lumen. A concentration gradient formed (with a higher concentration of protons in the thylakoid lumen than in the stroma).

How are protons pumped across the inner mitochondrial membrane?

The energy used in the electron transport chain pumps protons across the inner mitochondrial membrane from the inner matrix to the intermembrane space, producing a strong hydrogen concentration gradient. This process was called chemiosmosis by its discover, Peter Mitchell.

What complexes pump protons?

The ATP synthase complex, ADP and phosphate translocases. Protons are pumped out of the matrix at complexes I, III and IV (2 per complex).

What are the complexes in electron transport chain?

The ETC proteins in a general order are complex I, complex II, coenzyme Q, complex III, cytochrome C, and complex IV.

Where does oxidative phosphorylation occur?

Oxidative phosphorylation occurs in the mitochondria of all animal and plant tissues, and is a coupled process between the oxidation of substrates and production of ATP. As the Kreb’s cycle runs, hydrogen ions (or electrons) are carried by the two carrier molecules NAD or FAD to the electron transport pumps.

Where do protons escape through?

Protons are pumped out of the matrix into the intermembrane space (IMS) by complexes I, III, and IV of the electron transport chain. This establishes a proton motive force ( Δp) across the inner membrane. Proton re-entry through the ATP synthase (complex V) couples the release of Δp to ATP synthesis.

Where do protons come from in photosynthesis?

Just like in respiration, the proton gradient is generated across an internal membrane of the organelle. In photosynthesis, there are two sources of protons: some are transported into the thylakoid space by the electron transport chain, and some are produced in the thylakoid when PS II splits water.

When protons are pumped outside the matrix across the inner membrane?

Protons are pumped out of the matrix at complexes I, III and IV (2 per complex). The resulting proton gradient is used to drive ATP synthesis: 2 H+ per ATP produced. The proton gradient also creates a charge difference across the inner mitochon.

What is the path of electrons from NADH through the electron transport chain?

The path of electron flow is NADH → NADH dehydrogenase complex → ubiquinone → cytochrome b-c1 complex → cytochrome c → cytochrome oxidase complex → molecular oxygen (O2). The respiratory enzyme complexes couple the energetically favorable transport of electrons to the pumping of H+ out of the matrix.

How are protons pumped out?

Proton pumps are a special kind of transporter that push hydrogen ions from areas of low concentration to areas with high concentration. Ions moving down a gradient release energy, but when they move up a gradient, it takes energy. Diffusion can then use this gradient to capture energy again, as the ions move downhill.

What is electron transport chain and oxidative phosphorylation?

Oxidative phosphorylation is a process involving a flow of electrons through the electron transport chain, a series of proteins and electron carriers within the mitochondrial membrane. This flow of electrons allows the electron transport chain to pump protons to one side of the mitochondrial membrane.

What is the final complex in the electron transport chain?

Complex IV (Cytochrome c oxidase). This final complex in the electron transport chain accomplishes the final transfer of the electrons to oxygen and pumps two protons across the membrane.

How does the electron transport chain make use of proton potential?

This complex makes use of the proton potential created by the action of the electron transport chain. It transports a proton down the gradient and uses the energy to complete the phosphorylation of ADP to ATP.

How are Protons transferred across the inner mitochondrial membrane?

Three of the four complexes translocate protons across the inner mitochondrial membrane, thus generating the transmembrane electrochemical gradient. Five types of prosthetic groups are involved in electron transfer within the complexes. Complex I – NADH-Q oxidoreductase (Complex I) [EC 1.6.5.3]

What happens to the electron transport chain after DNP poisoning?

Show Answer After DNP poisoning, the electron transport chain can no longer form a proton gradient, and ATP synthase can no longer make ATP. DNP is an effective diet drug because it uncouples ATP synthesis; in other words, after taking it, a person obtains less energy out of the food he or she eats.