1) In the first step of the ETC,
an NADH molecule arrives at protein Complex I, also called NADH dehydrogenase
. Complex I receives two electrons from NADH, oxidizing it to NAD+. One hydrogen is pumped into the intermembrane space for each electron.
In what order do the electrons move through the ETC?
The electrons must travel through special proteins stuck in the thylakoid membrane. They go through the first special protein (the photosystem II protein) and down the electron transport chain. Then they pass through a
second special protein
(photosystem I protein).
What are the steps of the ETC?
- Step 1: Generating a Proton Motive Force.
- Step Two: ATP Synthesis via Chemiosmosis.
- Step Three: Reduction of Oxygen.
- Summary: Oxidative Phosphorylation.
What are the major components of ETC?
- Complex I = NADH-Q reductase complex.
- Complex III= Cytochrome c reductase complex.
- Cyt C = Cytochrome c.
- Complex IV = Cytochrome c oxidase complex.
What is the role of ETC?
The ETC is the
most important stage of cellular respiration
from an energy point of view because it produces the most ATP. In a series of redox reactions, energy is liberated and used to attach a third phosphate group to adenosine diphosphate to create ATP with three phosphate groups.
What is the relationship between ETC and oxygen?
Explanation:
Oxygen acts as the terminal electron acceptor in
the electron transport chain (ETC). This accounts for the reason as to why, when cells are starved of oxygen, the ETC “backs up” and the cell will divert to using anaerobic respiration, such as fermentation.
What is the function of ubiquinone?
Ubiquinone in a partially reduced form is found in all cell membranes. It
protects efficiently not only membrane phospholipids from peroxidation
but also mitochondrial DNA and membrane proteins from free-radical-induced oxidative damage.
Why do we use DCMU?
DCMU is a
very specific and sensitive inhibitor of photosynthesis
. It blocks the Q
B
plastoquinone binding site of photosystem II, disallowing the electron flow from photosystem II to plastoquinone. … Because of these effects, DCMU is often used to study energy flow in photosynthesis.
How are the components of the ETC arranged?
The components of the chain include
FMN, Fe–S centers, coenzyme Q, and a series of cytochromes (b, c1, c, and aa3)
. The energy derived from the transfer of electrons through the electron transport chain is used to pump protons across the inner mitochondrial membrane from the matrix to the cytosolic side.
What makes up ETC?
The electron transport chain is composed of
four protein complexes
, which are embedded in the inner membrane of the mitochondrion, along with two mobile carriers (mobile carrier Q {coenzyme Q} and mobile carrier C, that shuttle electrons through the ETC. The ETC is where the greatest amount of ATP is synthesized.
Where does ETC occur?
The electron transport chain is a series of four protein complexes that couple redox reactions, creating an electrochemical gradient that leads to the creation of ATP in a complete system named oxidative phosphorylation. It occurs
in mitochondria
in both cellular respiration and photosynthesis.
What happens if ETC is blocked?
In fact, if electron transport is blocked
the chemiosmotic gradient cannot be maintained
. … An inhibitor may competely block electron transport by irreversibly binding to a binding site. For example, cyanide binds cytochrome oxidase so as to prevent the binding of oxygen. Electron transport is reduced to zero.
What are the reactants of ETC?
The main biochemical reactants of the ETC are
the electron donors succinate and nicotinamide adenine dinucleotide hydrate (NADH)
. These are generated by a process called the citric acid cycle (CAC). Fats and sugars are broken down into simpler molecules such as pyruvate, which then feed into the CAC.
What is Kimi osmosis?
In biology, chemiosmosis refers to the
process
of moving ions (e.g. protons) to the other side of the membrane resulting in the generation of an electrochemical gradient that can be used to drive ATP synthesis. … Not only is chemiosmosis similar to osmosis.
What happens if oxygen is not present to capture electrons?
If oxygen isn’t there to accept electrons (for instance, because a person is not breathing in enough oxygen),
the electron transport chain will stop running
, and ATP will no longer be produced by chemiosmosis.
What is synthesis of ATP?
ATP synthesis involves
the transfer of electrons from the intermembrane space, through the inner membrane, back to the matrix
. … The combination of the two components provides sufficient energy for ATP to be made by the multienzyme Complex V of the mitochondrion, more generally known as ATP synthase.
