Non-Cyclic Photophosphorylation / Electron Flow: Pathway 2 Flashcards Preview

Biology: 11 - Photosynthesis > Non-Cyclic Photophosphorylation / Electron Flow: Pathway 2 > Flashcards

Flashcards in Non-Cyclic Photophosphorylation / Electron Flow: Pathway 2 Deck (20)
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1
Q

How many electrons leave the reaction centre chlorophyll in the cluster of pigments during non-cyclic photophosphorylation?

A

Two electrons leave the electron acceptor

2
Q

What happens to the two high-energy electrons when they leave the reaction centre chlorophyll?

A

They are passed to an electron acceptor and then along a series of electron acceptors

3
Q

Where do the events of non-cyclic photophosphorylation take place?

A

The grana of the chloroplast

4
Q

Why is this electron flow referred to as non-cyclic?

A

As the energised electrons do not return to the chloroplast

5
Q

Instead of retuning to the chlorophyll, what happens to the two high-energy electrons?

A

The two electrons combine with NADP+ to form NADP-

6
Q

What happens to the electrons as they move form electron acceptor to electron acceptor?

A

They lose energy which is trapped by ADP and a phosphate and then used to form ATP and water

7
Q

What do the electrons combine with to form NADP-?

A

NADP+

8
Q

What is formed when the two electrons combine with NADP+?

A

NADP-

9
Q

What combines with NADP+ to form NADP-?

A

2e-

To electrons

10
Q

What happens after NADP- has been formed?

A

The chlorophyll molecule is now short of electrons so it gains new electrons from the splitting of water - photolysis

11
Q

Define photolysis.

A

The splitting of water by light

12
Q

What is formed from the splitting of 2 water molecules?

3

A

4H+ (four protons)

4e- (four electrons)

O2 (oxygen gas)

13
Q

What happens to the protons formed by through photolysis?

A

They are stored in a proton pool in the chloroplast

14
Q

What happens to one of the protons stored in the proton pool?

A

One is attracted to NADP- and combines with it to reduce it to NADPH

15
Q

Give the chemical formula for the formation of NADP-.

A

NADP+ +2e- –> NADP-

16
Q

Give the chemical formula for the formation of NADPH.

A

NADP- + H+ –> NADPH

17
Q

What happens when a proton combines with NADP-.

A

The NADP- is reduced to NADPH

18
Q

What happens to the electrons formed by photolysis?

A

Two of the electrons replace the electrons lost by the chlorophyll which restores the number of electrons in the reaction centre chlorophyll

19
Q

What happens to the oxygen gas formed by photolysis?

2

A

Some is released out through the stomata into the atmosphere

Some is used internally in the plant in respiration

20
Q

What is this type of electron flow commonly called?

A

Non-cyclic electron flow