Biochem Quiz - ETC & Oxidative Phosphorylation

Q cycle

Q cycle

The shuttling of electrons between ubiquinol and ubiquinone in the inner mitochondrial membrane

Where does the Q cycle occur?

complex 3

What is the purpose of the Q cycle?

It links a two electron donor with a one electron carrier

Ubiquinone

electron transporter in the ETC that connects the first or second complex to the third

Ubiquinol

Reduced form of ubiquinone after it accepts electrons

What is complex I of the ETC?

NADH dehydrogenase

What is complex II of the ETC?

Succinate dehydrogenase

What is complex III of the ETC?

cytochrome c reductase

What is the purpose of Cytochrome C?

Shuttle electrons between complexes III and IV

What is complex IV of the ETC?

cytochrome c oxidase

What is Cytochrome C?

a small peripheral membrane protein located in the intermembrane space of mitochondria

What are the requirements for the ETC?

- Electron carriers (NADH & FADH2)
- Oxygen

Oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of the ETC

Ubiquinone to ubiquinol

Q + 2e- + 2H+ ⇌ QH2

Electron transport inhibitors

- directly inhibit electron transport, causing a decreased proton gradient and block of ATP synthesis

Complex I inhibitor

Rotenone and Amytal

Complex III inhibitor

Antimycin

Reactive Oxygen Species (ROS)

a group of extremely reactive peroxides and oxygen-containing radicals that may contribute to cellular damage

ATP synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

ATP synthase inhibitor

Oligomycin