Electron transport and oxidative phosphorylation combined

Question 1

What is the final step in non-photosynthetic energy conversion pathways?

Answer 1

Oxidative phosphorylation

Question 2

What can be inferred about the mitochondrial content of meat if it is darker?

Answer 2

Higher mitochondrial content

Question 3

What can be inferred about the mitochondrial content of meat if it is lighter?

Answer 3

Lower mitochondrial content

Question 4

In the chemiosmotic theory, what is the energy generated by redox reactions used to generate?

Answer 4

A proton gradient

Question 5

What two kinds of difference does a proton gradient create?

Answer 5

Chemical potential energy difference and an electrical potential energy difference?

Question 6

Across which membrane are the differences generated by proton gradients present?

Answer 6

Inner mitochondrial membrane

Question 7

What is the general flow of the protons in the proton gradient?

Answer 7

Pumped out of matrix, then diffuses back in via ATP synthase channels

Question 8

How does the proton circuit behave like an electrical curcuit?

Answer 8

Electrical circuit = H+, battery = ETC system, capacitor = H+ gradient and resistor = ATP synthase

Question 9

What can happen to the ETC, causing ATP synthase to cease?

Answer 9

The redox energy can be uncoupled form the ATP synthase channels

Question 10

How is the ETC uncoupled from the ATP synthase channels?

Answer 10

The H+ diffuse back into the mitochondrial membrane via an uncoupler protein instead of the ATP synthase channel

Question 11

What is the purpose of the uncoupler proteins in the inner mitochondrial membrane?

Answer 11

The energy generated by the ETC is converted into heat instead of ATP

Question 12

What do blockers do in the ATP synthase channel?

Answer 12

Prevent any H+ from diffusing back into the mitochondrial matrix

Question 13

Why are blockers used in the inner mitochondrial membrane?

Answer 13

deltapH and deltaWaterPotential across the inner mitochondrial membrane both increase, eventually leading to cell death

Question 14

What is useful about using uncoupler proteins to generate heat?

Answer 14

They generate a large amount of heat in a small time–> newborn mammals can use it

Question 15

Four ways to transfer electrons from donor to acceptor?

Answer 15

Directly as electrons
As hydrogen atoms
As a hydride ion (:H-)
Direct combination with oxygen

Question 16

What type of electron transport does not occur in oxidative phosphorylation?

Answer 16

Direct combination with oxygen

Question 17

Example of transferring electrons directly as electrons?

Answer 17

Fe2+ + Cu2+ <—->Fe3+ + Cu+

Question 18

Example of transferring electrons as hydrogen atoms?

Answer 18

AH2 <—->A + 2e- + 2H+

Question 19

Example of transferring electrons as hydride ions?The ten

Answer 19

Moving a :H- (which comprises a proton and two electrons)

Question 20

What does redox potential measure?

Answer 20

measure of the tendency of a chemical species to acquire electrons from or lose electrons to an electrode

Question 21

What can be said about a compound/ion if it has a negative redox potential?

Answer 21

Strong reducing agent

Question 22

What can strong reducing agents do?

Answer 22

Easily donate electrons

Question 23

What can be said about a compound/atom if it has a positive redox potential?

Answer 23

Strong oxidising agent

Question 24

What can strong oxidising agents do?

Answer 24

Easily accept electrons

Question 25

What pH are standard redox potentials measured at?

Answer 25

7