Lecture 23 and 24: Oxidative Phosphorylation and ETC

Question 1

Respiration

Answer 1

Oxidation of organic compounds in cells to produce energy

Question 2

Cytochrome

Answer 2

Membrane bound heme protein

Question 3

Electron Transport Chain

Answer 3

Series of compounds, including enzymes, that move electrons down via redox reactions, coupled with proton transfer

Question 4

Complex I

Answer 4

NADH Dehydrogenase; FMN accepts two electrons from NADH and passes them single to Fe-S transfers these to CoQ. Protons are moved across the membrane during this step.

Question 5

Complex II

Answer 5

Succinate Dehydrogenase, part of the TCA cycle. Also passes electrons to CoQ. Does NOT span the membrane and does NOT have proton-pumping mechanisms.

Question 6

Complex III

Answer 6

Cytochrome reductase: receives electrons from complex I via CoQ, passing these to cytochrome C
Has Iron-containing heme prosthetic group

Question 7

Complex IV

Answer 7

Cytochrome oxidase: Contains heme and copper.

Transfers electrons to O2, producing water

Question 8

Complex V

Answer 8

ATP Synthase with innermembrane F0 and outer F1 head and stalk. Uses proton gradient to produce ATP.

Question 9

Coenzyme Q

Answer 9

Only component of ETC not protein-bound. Shuttle electrons between complexes I and III, accepting 1 or 2 protons.
If in oxidized form a single electron it forms a free radical

Question 10

Coenzyme QH2

Answer 10

Dihydroquinol, reduced/quinol form of CoQ

Question 11

Oxidative Phosphorylation

Answer 11

The process in which ATP is formed as a result of the transfer of electrons from NADH or FADH2 to O2 by a series of electron carriers

Question 12

Proton Motive Force

Answer 12

Force that promotes the movement of protons across a membrane and down the electrochemical gradient