Oxidative phosphorylation (Electron Transport Chain and Chemiosmosis)

What is oxidative phosphorylation?

This term refers to the mitochondrial process that uses oxygen and high=-energy electrons to produce ATP and water (electron transport chain plus chemiosmosis)

What comes from the Krebs/Citric Acid Cycle to be used by the Electron Transport Chain?

electrons carried by the co-enzymes NADH and FADH2

What is a redox reaction?

the movement of electrons from one molecule to another

Where do redox reactions occur?

In the electron transport chain

electron transport chain is a series of

Proteins that use electrons to pump hydrogen ions/protons into the inner membrane

Why does it require energy to push protons/Hydrogen ions across the matrix and into the membrane?

There are already more hydrogen ions/protons inside the membrane, so they have to be pumped against the concentration gradient from low to high concentration

At the end of the electron transport chain , what is the final electron acceptor?

oxygen

Where does the water come from at the end of the electron transport chain?

The O2 molecule splits, absorbs 2 hydrogens, and makes H20 water

Where does the water go at the end of the electron transport chain?

We breathe it out

What is chemiosmosis?

Hydrogen ions/Protons cross the ATP synthase across teh membrane into the matrix from high to low concentration. This turns the ATP synthase and attaches a phosphate to ADP, creating an ATP molecule.

How many ATP molecules are formed at chemiosmosis?

32 (theoretical)

Cyanide poisoning inhibits Complex IV, making it unable to transport electrons. What effect would this have?

The electron transport chain would stop. Then there would be no hydrogen to run through the ATP synthase. Not enough ATP energy formed=death

Dinitrohenol (DNP makes the inner mitochondrial membrane leaky to protons/hydrogen ions. It was used until 1938 as a weight loss drug. How would DNP affect ATP production?

DNP allows protons to travel down their gradient and back into the mitochondrial matrix without passing through ATP synthase, reducing ATP production. The energy of the gradient is dissipated in the form of heat, raising body temperature. DNP was removed from the market because it caused deaths due to hyperthermia (severely elevated body temperature), and also because it was linked to cataracts and vision loss.