Light Stage - Transfer Of Energy To Electrons

Question 1

How are pigments arranged in the chloroplast?

Answer 1

Pigments are arranged in clusters in the chloroplast

Question 2

What are arranged in clusters in the chloroplast?

Answer 2

Pigments

Question 3

What does each cluster of pigments consist of?

3

Answer 3

A variety of pigments

A strategically placed chlorophyll molecule

An electron acceptor

Question 4

What is the strategically placed chlorophyll molecule in a cluster of pigments called?

Answer 4

The reaction centre chlorophyll

Question 5

Where is the reaction centre chlorophyll located?

Answer 5

It is strategically located beside an electron acceptor

Question 6

How many chlorophyll molecules is there in a cluster of pigments?

Answer 6

There can be many chlorophyll molecules but there is only one strategically placed beside an electron acceptor i.e. there is only one reaction centre chlorophyll

Question 7

What is located beside the electron acceptor in a cluster of pigments?

Answer 7

The reaction centre chlorophyll

Question 8

What is the reaction centre chlorophyll?

Answer 8

A chlorophyll molecule located strategically beside an electron acceptor in a cluster of pigments

Question 9

What happens in each cluster when light is available?

Answer 9

In each cluster, the different pigments absorb light energy of different wavelengths (colours)

Question 10

What is the function of the cluster of pigments?

Answer 10

To absorb as much light as possible

Question 11

What happens after the different wavelengths (colours) of light have been absorbed by the different pigments in each cluster?

Answer 11

The different pigments transfer the absorbed energy from one to another until it reaches the reaction centre chlorophyll associated with the electron acceptor

Question 12

What happens when the absorbed energy reaches the reaction centre chlorophyll associated with the electron acceptor

Answer 12

Here the energy is transferred to electrons, causing them to become energised/high-energy electrons

Question 13

What happens to the electrons once they have become energised?

Answer 13

They are passed from the chlorophyll to the electron acceptor

Question 14

Where do the electrons become energised?

Answer 14

The reaction centre chlorophyll

Question 15

What happens to the electrons once they have been passed to the electron acceptor?

Answer 15

They then flow from the electron acceptor along one of two different pathways

Question 16

Name the two pathways that the energised electrons may flow along.

Answer 16

Electron flow: Pathway 1 - cyclic photophosphorylation

Electron flow: Pathway 2 - non-cyclic photophosphorylation