The Pathways of Oxidative Phosphorylation

1. The Pathways of OxidativePhosphorylation By A-aron L. and Jay-Crisp

2. Whole Show

3. The Pathway of Electron Transport • The electron transport chain is a collection of molecules embedded in the inner membrane of the mitochondria in Eukaryotic cells. • Most components in a chain are protein • Exists in multi-protein complexes Number 1-4 • Bound to these proteins are prosthetic groups and these are non-protein components essential for catalytic enzymes.

4. ATP Molecular Mill • H+ Ions flowing down their gradient enter a half channel in a stator, which is anchored in the membrane. • H+ Ions enter binding sites within a rotor, changing the shape of each subunit so that the rotor spins within the membrane. • Each H+ Ion makes one complete turn before leaving the rotor and passing through a second half channel in the stator into the mitochondrial matrix. • Spinning of the rotor causes as internal rod to spin as well. This rod extends like a stalk into the knob below it, which is held stationary by part of the stator. • Turning of the rod activates catalytic sites in the knob that produce ATP from ADB and P

5. Yo Dog, What’s the Pathway to E-Trans. • Most of the remaining electron carriers between ubiquinone and oxygen are proteins call Cytochromes. • Prosthetic group, called a heme group • Has an Iron Atom that accepts and donates electrons. • The electron transport chain has several types of cytochromes each a different protein with a slightly different electron carrying heme group. • The electron transport chain does not produce ATP directly • Breaks down larger molecules in a Nine Fold Process until they becomes small enough, producing ATP as a product and H2O as a Bi-Product which then leads to CHEMIOSIS

6. Chemiosmosis

7. Chemiosmosis • Populating the inner membrane of the mitochondrion or the prokaryotic plasma membrane are many copies of a protein complex, Called ATP Synthase • The enzyme that makes ATP from ADP and Inorganic Phosphate • ADP+ P = ATP

8. Chemiosmosis and Oxidative Phosphorylation • There is an electrochemical gradient across the cristae • Two Parts: • Difference in charge • Difference in Concentration

9. Electrochemical Gradient The diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane and the ions tendency to move relative to the membrane potential….

10. Chemiosmosis and Oxidative Phosphorylation • The Inner membrane is impermeable to protons. • The protons are forced through special proton channels that are coupled with ATP synthase

11. Chemiosmosis and Oxidative Phosphorylation • The electrochemical gradient produces a proton-motive force (PMF) that moves the protons through this ATPase complex. • Each time a proton comes through the ATPase complex, the free energy of the electrochemical gradient is reduced and this energy is used to create ATP from ADP + P in the matrix.

12. Who found this out? • Peter Mitchell found all this out in 1961 and coined the term chemiosmosis because the energy that drives ATP production comes from the osmosis of protons. It took a long time for his theory to be accepted. He finally got his Nobel Prize in 1978.

13. Here yur GUR!!!