Oxidative phosphorylation

Question 1

where does it take place

Answer 1

mitochondria electron transport chain

Question 2

where is the electron transport chain located in the mitochondria in op

Answer 2

on the inner mitochondrial membrane

Question 3

what is chemiosmosis

Answer 3

flow of protons down their conc gradient across a membrane associated with atp synthase

Question 4

what does atp synthase do

Answer 4

catalyses the synthesis of atp from adp + pi

Question 5

what is oxidative phosphorylation

Answer 5

formation of atp using energy released from the electron transport chain in the presence of oxygen.

Question 6

why is it beneficial for mitochondria to be folded

Answer 6

It increases the surface area for atp synthase enzymes and electron carrier proteins

Question 7

What is the first step of oxidative phosphorylation

Answer 7

reduced nad and fad (from the krebs cycle) are reoxidised as they donate hydrogen atoms to the electron transport chain in the inner membrane of the mitochondria

Question 8

After the Reduced NAD and FAD have been reoxidised, what happens?

Answer 8

their hydrogen atoms are split into protons and electrons

Question 9

After Reduced NAD and FAD are oxidised, their hydrogen atoms are split into protons and electrons. Where do these products go

Answer 9

The electrons enter the etc, this releases energy to transport protons from the matrix, over the inner membrane, into the intermembrane space

Question 10

how many ATP molecules are produced during oxidative phosphorylation

Answer 10

28 per one glucose molecule

Question 11

a proton gradient in achieved through the transport of proteins, but what area of the mitochondrion does this gradient occur

Answer 11

low conc- in the matrix

Over the inner membrane

high conc- intermembrane space

Question 12

what ion is in the core of the elctron carrier protein and what does it do

Answer 12

iron ion

Function- it gains the electrons to become reduced, it can then donate the electron to the next iron ion at the next electron carrier protein

Question 13

as electrons pass down the etc, energy is released, what is this energy used for

Answer 13

some of the energy is used to pump protons across the inner membrane from the matrix to the intermembrane space

Question 14

Why do protons have to diffuse through membranes associated with atp synthase, rather than just traveling through

Answer 14

Because the membrane is impermeable to protons as they have a charge.

Question 15

As protons diffuse down their gradient from the intermembrane space back to the matrix, it has an effect on the atp synthase. What is this effect

Answer 15

The flow of protons can cause a comformational change in the atp synthase.
this allows ADP and PI to combine

Question 16

when does chemiosmosis occur

Answer 16

WHen the protons have accumulated in the space, the flow of protons out of that space through the atp synthase channel, into the matrix. This is chemiosmosis

Question 17

What is the final electron acceptor

Answer 17

Oxygen

Question 18

what are the molecules which oxygen accepts at the end of oxidative phosphorylation

Answer 18

Oxygen accepts Hydrogen ions and electrons to produce a water molecule

Question 19

what is the total amount of atp produced by respiration

Answer 19

32

Question 20

The yield of atp is usually lower, what are some reasons for this

Answer 20

Some atp is used to actively transport pyruvate into the mitochondria

some protons may leak out the outer mitochondrial membrane

Question 21

the transport of protons is an active process but doesnt require atp, what energy does it use

Answer 21

It uses the energy released from the transport of electrons down their electron transport chain