Cell Integrity

Question 1

Where does oxidative phosphorylation occur

Answer 1

Inner membrane in contrast to the Krebs Cycle which takes place in the matrix

Question 2

What are the four membrane proteins in the ETC

Answer 2

NADH Dehydrogenase complex( Complex 1)
Succinct-Q reductase ( Complex II)
Cytochrome b-c1 ( COMPLEX III)
Cytochrome oxidase complex ( complex IV)

Question 3

What are the two carriers in the ETC

Answer 3

Ubiquinone ( co enzyme Q ) and cytochrome C

Question 4

Why does FADH2 produce less ATP per molecule

Answer 4

Succinate dehydrogenase ( complex 2) can communicate directly withubiquinone so no need for complex 1 so one less proton is pumped to inter membrane space and so less ATP is produced

Question 5

What does a negative redox potential imply

Answer 5

Redox couple has a tendency to donate electrons and therefore has a greater reducing power than hydrogen

Question 6

What are the two parts of the ATP enzyme

Answer 6

FO which is membrane bound and F1 which projects into the matrix space

Question 7

What determine ATP synthesis vs ATP hydrolysis

Answer 7

Proton flow ( more protons in matrix - ATP hydrolysis). Think about OP

Question 8

In an oxygen electrode the resulting current is therefore …..

Answer 8

Proportional to the oxygen conc in the sample chamber. Can use this with mitochondria to investigate the various components of ETC

Question 9

What is the most common cause of failure of oxidative phosphorylation

Answer 9

Lack of oxygen eg. Hypoxia and anoxia

Question 10

What are the 2 processes via which metabolic poisons work

Answer 10

They interfere with either
The flow of electrons along ETC
The flow of protons along ATP synthase
Basically interrupt ATP synthesis

Question 11

CAMROD

Answer 11

Cyanide,Azide, Malonate, Rotenone, oligomycin, dinitrophenol

Question 12

Cyanide and azide

Answer 12

Binds with high affinity to ferric form of Haem group in the cytochrome oxidase complex ( IV) blocking final step of ETC

Question 13

Malonate

Answer 13

Closely resembles succinate and acts as comp inhibitor of succinate dehydrogenase. It slows down flow of electrons from succinate to uniquinone by inhibiting oxidation of succinate to fumarate

Question 14

Rotenone

Answer 14

Inhibits transfer of electrons from complex I to ubiquinone

Question 15

Oligomycin

Answer 15

Binds to FO and blocks flows of protons through ATP synthase

Question 16

DNP

Answer 16

Uses another channel to transport protons instead of going via ATP channel so no ATP made. But can induce weight loud as more 02 formed so heightened metabolic rate and fat metabolism. Lots of energy lost as heat ( leading to non shivering thermogenesis)