Cell Bio- Oxidative Phosphorylation

Ox. Phos. requires:

1. O2 as the terminal electron acceptor

2. ETC

3. PMF

4. ATPase

5. Membrane

What is the Electron Transport Chain?

A series of membrane protein complexes that shuttle electrons down the membrane

Located in the inner mitochondrial membrane

Ox. Phos. requires:

1. O2 as the terminal electron acceptor

2. ETC

3. PMF

4. ATPase

5. Membrane

What is the Electron Transport Chain?

A series of membrane protein complexes that shuttle electrons down the membrane

Located in the inner mitochondrial membrane

What are the two main functions of ETC

1. Allow electrons to flow from one complex to the next, releasing energy

2. Pump protons across a membrane, to make PMF

ETC uses what?

The energy of electron motion as a power source. It is spontaneous and releases energy

What are complexes I and II

Flavoproteins (vit. B2)

What are complexes III and IV and cytochrome c?

Cytochromes (have heme group and Fe2+)

Coenzyme Q and cytochrome c are:

Mobile electron carriers that move sideways in the inner membrane and shuttle electrons between complexes

What is a heme group?

It is a porphyrin ring plus iron

What complexes moves through the ETC?

Complexes I, III, IV use the energy of e- movement through the complex to pump H+

What is the proton motor force located?

A gradient of H+ forms in the intermembrane space between the inner and outer membranes. It is the high concentration of protons in the intermembrane space

What is the PMF?

The potential energy stored in a gradient of protons across a membrane

H+ are trapped

What are the two forces PMF has?

A chemical force and an electrical force

What is a membrane potential?

The voltage difference across a membrane. Created by the separation of opposite charges

What is chemiosmosis?

An energy coupling that uses energy from a proton gradient to drive cellular work

Ex: making ATP using ATP synthase and rotating a flagella

What is ATP synthase?

H+ flowing through ATPase causes it to rotate

It is powered by the PMF, mechanical energy is transformed into chemical energy