chemiosmosis: energy coupling mechanism

Question 1

ATP synthase

Answer 1

enzyme that makes ATP from ADP +Pi

–uses energy of existing ion gradient to power ATP synthesis

Question 2

how does ATP synthase work

Answer 2

as H+ diffuses across the membrane, protons move into binding sites on different parts of rotors causing it to spin in a way that catalyzes ATP production from ADP to ATP

Question 3

how is the chemiosmosis gradient created

Answer 3

throughout the ETC, the exergonic flow of electrons pumps H+ into the inter membrane space.

–when H+ diffuses down its gradient, the ATP synthase is the only place that they can diffuse back across the membrane

Question 4

how is H+ pumped outside the membrane

Answer 4

certain places in the ETC release protons as well as electrons
–at these steps, electron transfer causes H+ to be taken and released into the surrounding solution.

Question 5

in eukaryotes, how are H+ pumped across the membrane

Answer 5

electron carriers are spatially placed in the membrane that h+ is accepted fro the mitochondrial matrix and deposited in the inter membrane space

Question 6

the H+ gradient that results from pumping H+ out

Answer 6

proton motive force

–this force drives h+ back across the membrane through ATP Synthase

Question 7

chemiosmosis

Answer 7

an energy coupling mechanism that used energy stored in form of H+ gradient across a membrane to drive cellular work

Question 8

what makes ATP

Answer 8

H+ flowing through ATP synthase

Question 9

how does tap synthase work

Answer 9

it has 4 parts

-protons bind to sites one by one, spinning it in a way that catalyses ADP + i->ATP

Question 10

how does the inner mitochondrial membrane generate and maintain the H+ gradient

Answer 10

the chain uses the exergonic flow of electrons from NADH and FADH2 to pump excess H+ across membrane into inter membrane spaces

Question 11

proton motive force

Answer 11

the h+ gradient that results

-the gradient forces h+ back across the membrane