Chapter 14 - Energy Conversion in the Mitochonrion

Chemiosmotic coupling takes the energy from the sun to produce a proton gradient

Mitochondria tend to associate with microtubules within a cell. There can be over 100 in each cell on average minimum. There are more mitochondria where more ATP is needed, such as in the muscles. They also provide movement energy

Anatomically, the mitochondria has an outer eukaryotic membrane and an inner prokaryotic membrane. This means only the outer has cholesterol, and the overall composition of lipids is slightly different. Porins are on the outside, not the inside. Cristae are foldings of the inner membrane, leading to a larger surface area for the inner membrane. This is varied from cell to cell. There is an intermembrane space between outer and inner membranes, and the outer is more permissible while the inner isn’t.

The intermembrane space has a high proton concentration, the gradient is higher outside than inside. The overall pH or cytosol and intermembrane space isn’t that different, but the inner-mitochondrial matrix has a pH of 8, with much less protons. Pumps exist to remove protons from the mitochondrial matrix

The ETC also makes NADH into NAD+, allowing it to reenter the Kreb’s cycle

The rate of electron flow relies on the rate of ATP production, and the rate of food that is broken down. This path has no key enzyme, and only relies on oxygen supply and proton supply.

The respiration chain is the ETC, and occurs within the crista. There is one entry for electrons, which are transported to the other pumps. Each pump is Complex I, Complex III, and complex 4. Ubiquinone (CoQ) brings electrons from I to III. Cytochrome C transports electrons from III to IV. IV undergoes the redox reaction to form water. All of the reactions are redox reactions