Photosynthesis

Question 0

In the first stage, pathways I and II relate to the passage of energised electrons.
explain what happens to these electrons in pathway I.

Answer 0

Electrons picked up by an acceptor passed trough carriers

Passed back to chlorophyll

Question 1

Give the name of the first stage.

Answer 1

Lightstage

Question 2

Describe the events of pathway II

Answer 2

1) water splits
2) Protons to pool/ NADP- formed
3) NADPH formed/ Oxygen released

Question 3

Give the name of the second stage

Answer 3

Dark stage / Light independent stage

Question 4

Give one reason why the second stage cannot happen without the first stage.

Answer 4

2nd stage needs end products if 1st stage - ATP and NADPH

They are necessary for dark stage reactions

Question 5

Suggest one possible benefit to plants of having more than one chlorophyll pigment.

Answer 5

More light can be absorbed

-> leads to increased Photosynthesis

Question 6

What is the main source of carbon dioxide used by plants in the dark stage of photosynthesis?

Answer 6

Air

Question 7

State one role of NADP and one role of ATP in the dark stage of photosynthesis.

Answer 7

NADP - transport electrons

       - transport energy
       - transport Protons / H+

ATP - provides Energy

Question 8

Where in a plant cell does photosynthesis take place?

Answer 8

Chloroplast

Question 9

Give the alternative name of the first stage of photosynthesis.

Answer 9

Lightstage

Question 10

During the first stage of photosynthesis energised electrons enter two pathways.
Where do the energised electrons come from?

Answer 10

Come from Chlorophyll

Question 11

Name the simple compound that supplies the necessary energy for the second stage reactions.

Answer 11

ATP

Question 12

Name the substance X, formed by the loss of a phosphate group.

Answer 12

ADP

Question 13

The ATP cycle is kept going by Y, what is Y?

Answer 13

Energy

Question 14

Name the openings in the leaf which allow the entry of carbon dioxide for photosynthesis. State a factor which influences the diameter of these openings.

Answer 14

Stomata

Light/ temperature

Question 15

During photosynthesis oxygen is produced.

1) From what substance is oxygen produced?
2) In which stage of photosynthesis is oxygen produced?
3) Give two possible fates of oxygen following its production.

Answer 15

1) Water
2) lightstage
3) Respiration or diffuses into atmosphere

Question 16

What is the primary role of chlorophyll?

Answer 16

It traps light

Question 17

What is the equation of photosynthesis?

Answer 17

6Co2 + 6H2o + light -chlorophyll-> C6H12O6+6o2

Question 18

Name a gas that is essential for the dark stage.

Answer 18

Carbon dioxide

Question 19

Two products of the light stage are vital for the dark stage. Name each of them.

Answer 19

NADPH - protons & electrons

ATP - energy

Question 20

To what group of biomolecules do the main products of the dark stage belong?

Answer 20

Carbohydrates

Question 21

Outline major events of second stage.

Answer 21

Sugar formed from CO 2
ATP provides energy
NADPH provides hydrogen (H)