light-dependent reaction 11.2 Flashcards
what is oxidation?
when a substance gains oxygen or loses a hydrogen.
what is reduction?
when a substance loses an oxygen or gains a hydrogen
is energy given out or taken in when oxidation takes place>
given out
is energy given out or taken in during reduction.
taken in
what happens when light hits a chlorophyll molecule?
the light energy is absorbed and an electron is excited.
what is the process called when an electron is excited and taken away from the chlorophyll?
photoionisation.
what picks up the excited electron
an electron carrier.
what has happened to the chlorophyll molecule during this process.
it has been ionised/oxidised.
what has happened to the electron carrier.
it has been reduced
what happens to the electrons after they have been picked up by an electron carrier.
they are passed along a number of electron carriers through a series of oxidation reduction reactions.
where are these electron transport chains located?
in the membranes of the thylakoid.
what is the difference between the each carrier in the transport chain and the previous one?
each one is at a slightly lower energy level than the previous one
what is the energy lost in between electron carriers used for
creations of ATP from ADP and Pi
what is the first stage of the chemiosmotic theory?
Each thylakoid is an enclosed chamber in which protons are pumped from the stroma using protein carriers in the thylakoid membrane called proton pumps.
where does energy for the chemiosmotic theory come from
photolysis of water.
what does the photolysis of water produce apart from energy and why is this important?
protons because it furthers the concentration gradient between the thylakoid space and stroma
how do protons pass from a high concentration in the thylakoid space to a low concentration in the stroma?
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.
when chlorophyll is struck by light it loses an electron but this must be replaced, how is it replaced.
through the photolysis of water.
what is he equation for the photolysis of water.
2H20 –> 4H+ + 4E- + O2
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?
NADP
It is reduced.
where is reduced NADP mainly used?
light independent reaction
what is the main product of the light dependent reaction?
reduced NADP
what property does the thylakoid membrane grant to the chlorophyll that is beneficial to the light dependent reaction
large surface area
why is it important that the chloroplasts contain both DNA and ribosomes?
so they can quickly and easily manufacture some of the proteins involved in the light dependent reaction.
