light-dependent reaction 11.2

Question 1

what is oxidation?

Answer 1

when a substance gains oxygen or loses a hydrogen.

Question 2

what is reduction?

Answer 2

when a substance loses an oxygen or gains a hydrogen

Question 3

is energy given out or taken in when oxidation takes place>

Answer 3

given out

Question 4

is energy given out or taken in during reduction.

Answer 4

taken in

Question 5

what happens when light hits a chlorophyll molecule?

Answer 5

the light energy is absorbed and an electron is excited.

Question 6

what is the process called when an electron is excited and taken away from the chlorophyll?

Answer 6

photoionisation.

Question 7

what picks up the excited electron

Answer 7

an electron carrier.

Question 8

what has happened to the chlorophyll molecule during this process.

Answer 8

it has been ionised/oxidised.

Question 9

what has happened to the electron carrier.

Answer 9

it has been reduced

Question 10

what happens to the electrons after they have been picked up by an electron carrier.

Answer 10

they are passed along a number of electron carriers through a series of oxidation reduction reactions.

Question 11

where are these electron transport chains located?

Answer 11

in the membranes of the thylakoid.

Question 12

what is the difference between the each carrier in the transport chain and the previous one?

Answer 12

each one is at a slightly lower energy level than the previous one

Question 13

what is the energy lost in between electron carriers used for

Answer 13

creations of ATP from ADP and Pi

Question 14

what is the first stage of the chemiosmotic theory?

Answer 14

Each thylakoid is an enclosed chamber in which protons are pumped from the stroma using protein carriers in the thylakoid membrane called proton pumps.

Question 15

where does energy for the chemiosmotic theory come from

Answer 15

photolysis of water.

Question 16

what does the photolysis of water produce apart from energy and why is this important?

Answer 16

protons because it furthers the concentration gradient between the thylakoid space and stroma

Question 17

how do protons pass from a high concentration in the thylakoid space to a low concentration in the stroma?

Answer 17

they pass through a channel called the ATP synthase channel which changes the structure of an enzyme which catalyses the combination of ADP and Pi to from ATP.

Question 18

when chlorophyll is struck by light it loses an electron but this must be replaced, how is it replaced.

Answer 18

through the photolysis of water.

Question 19

what is he equation for the photolysis of water.

Answer 19

2H20 –> 4H+ + 4E- + O2

Question 20

when protons pass through the ATP synthase channel what are they picked up by? and what happens to it when it picks up a proton?

Answer 20

NADP

It is reduced.

Question 21

where is reduced NADP mainly used?

Answer 21

light independent reaction

Question 22

what is the main product of the light dependent reaction?

Answer 22

reduced NADP

Question 23

what property does the thylakoid membrane grant to the chlorophyll that is beneficial to the light dependent reaction

Answer 23

large surface area

Question 24

why is it important that the chloroplasts contain both DNA and ribosomes?

Answer 24

so they can quickly and easily manufacture some of the proteins involved in the light dependent reaction.

Question 25

why is it important to have ATP synthase channels in the granal membrane

Answer 25

because they are selectively permeable which allows them to establish a proton gradient and they catalyse the production of ATP