Photosynthesis

Question 1

What two reactions are forms of photosynthesis

Answer 1

Light dependent

Light independent

Question 2

Name two types of photosynthetic pigments

Answer 2

Chlorophylls

Carotenoids

Question 3

Why is it beneficial to a plant to have more types of photosynthetic pigments

Answer 3

Different pigments absorb different wavelengths of light and so the more different types of pigments the greater range of the wavelengths they are able to absorb.

Question 4

What is chlorophyll A known as

Answer 4

The primary pigment

Question 5

What are all types of pigments other than chlorophyll A known as

Answer 5

Accessory pigments

Question 6

What is a photosystem

Answer 6

a collection of accessory pigments which pick up light at various wavelengths and funnel this energy to the reaction centre, a chlorophyll A molecule

Question 7

Which mineral ion is a key component of chlorophyll

Answer 7

Magnesium

Question 8

What is photolysis

Answer 8

The splitting of water molecules into 2H+ and 1/2O2

Question 9

What is photophosphorylation

Answer 9

Adding phosphate using light

Question 10

What is the role of NADP in photosynthesis

Answer 10

Acts as a hydrogen carrier and is reduced to become red.NADP

Question 11

Where do the electrons come from which replace those lost from photosystem 2 during non-cyclic phosphorylation

Answer 11

The photolysis of water

Question 12

Where do the electrons come from which replace those lost in photosystem during non-cyclic phosphorylation

Answer 12

From photosystem 2

Question 13

Where do the electrons and hydrogens come from which enable NADP to be reduced

Answer 13

The electrons come from photosystem 1 and the hydrogens come from the photolysis of water

Question 14

What is done with the oxygen produced from non-cyclic phosphorylation

Answer 14

It is released as a waste product

Question 15

What is cyclic phosphorylation

Answer 15

This only involves photosystem 1. The electrons released return back to the photosystem they were promoted from

Question 16

What drives the light independent reaction

Answer 16

Enzyme called RuBISCO

Question 17

How is CO2 used in the light independent reaction

Answer 17

It is fixed to RuBP

Question 18

List the molecules formed in the Calvin Cycle

Answer 18

RuBP
Unstable Intermediate
Glycerate 3-phosphate
Triose Phosphate
RuBP
etc...

Question 19

Where is ATP used in the Calvin Cycle

Answer 19

Between Glycerate 3-phosphate and Triose phosphate, and between Triose Phosphate and RuBP

Question 20

Where is glucose produced in the Calvin Cycle

Answer 20

The synthesis of Triose Phosphate

Question 21

What happens to the ADP + Pi and NADP after the Calvin Cycle

Answer 21

It returns to the light dependent reaction to be used there

Question 22

What is an absorption spectrum

Answer 22

how much light a particular pigment absorbs at each wavelength

Question 23

What is an action spectrum

Answer 23

The rate of photosynthesis at different wavelengths of light

Question 24

How did Englemann’s Experiment work

Answer 24

He used respiring bacteria that had the ability to move and noted that they moved to areas of oxygen density to identify that photosynthesis takes place in the chloroplasts

Question 25

Name factors that limit photosynthesis

Answer 25

``` Light intensity Carbon Dioxide Water Minerals Temperature Chlorophyll ```

Question 26

What is the light compensation point

Answer 26

The light intensity at which a plant has no net gas exchange as the volume gases used and produced

Question 27

What is the light saturation point

Answer 27

Any increase in the light intensity striking the leaf does not cause an increase in the rate of photosynthesis

Question 28

What is the light saturation point indicated by

Answer 28

The level of O2 being evolved levels off

Question 29

Name some adaptations that sun plants have

Answer 29

``` Smaller surface area Leaf blade is thicker Palisade layer is thicker Fewer Chloroplasts Less accessory pigments ```

Question 30

Name some adaptations that shade plants have

Answer 30

``` Bigger surface area Thinner leaf blade Thinner Palisade layer More chloroplasts More accessory pigments ```

Question 31

How is nitrogen deficiency shown in plants

Answer 31

Plants with low levels of nitrates have older leaves that turn yellow and die. Their growth is also stunted.

Question 32

How is magnesium deficiency shown in plants

Answer 32

A lack of magnesium causes both old and new leaves to turn to yellow and growth to slow down