Section 5:Photosynthesis

Question 1

Where does photosynthesis take place?

Answer 1

Chloroplasts within the leaf

Question 2

What is the balanced symbol equation for photosynthesis?

Answer 2

6CO2+6H2O
—->C6H12O6+6O2

Question 3

What do plants convert light energy into?

Answer 3

ATP

Question 4

What are the three main stages of photosynthesis?

Answer 4

1. Capturing light energy by chlorophyll
2. The light-dependent recation
3. The light-indeprendent reaction

Question 5

What is chlorophyll and what is its role?

Answer 5

Pigment which is responsible for trapping light energy

Question 6

What are the parts of the chlorophyll?

Answer 6

Granum,stroma,thylakoid,
thylakoid space and inner/outer membrane

Question 7

What are thylakoids?

Answer 7

Contain the chlorophyll,enzymes and electron carriers
Site of light-dependent reaction

Question 8

What are grana(granum)?

Answer 8

Stacks of thylakoids

Question 9

What is the stroma?

Answer 9

The surrounding fluid containing enzymes. Site of the light-indeprendent raction

Question 10

What are the two reactions involved in photosynthesis?

Answer 10

1. Light-dependent
2. Light-independent

Question 11

What does the light-dependent reaction use light energy for?

Answer 11

To split water in order to make ATP & reduced NADP and oxygen

Question 12

Why does the ligh-independent reaction stop in the absence of light?

Answer 12

The light-independent reaction requires the products of the light-dependent stage (ATP and reduced NADP)

Question 13

What is ATP?

Answer 13

A form of chemical energy stored in a compound

Question 14

What are the components of ATP?

Answer 14

Ribose (5 carbon) sugar, adenine and three phosphate groups

Question 15

What is the equation involving ATP which produces energy?

Answer 15

ATP—>ADP+Pi+energy

Question 16

What is photolysis?

Answer 16

Using light energy to split water

Question 17

Five points

Describe how the light-dependent reaction of photosynthesis generates ATP

Answer 17

1.Light energy raises the energy level of electrons in the chlorophyll
2.Electrons pass down electron transfer chain
3.Electrons reduce carriers
4.Energy released
5.ATP generated from ADP and inorganic phosphate

Question 18

What are the limiting factors of photosynthesis?

Answer 18

Carbon dioxide concentration, light intensity, water, mineral ions and temperature

Question 19

How can the supply be increased for each limiting factor?

Answer 19

• Carbon dioxide=pump in gas or paraffin heaters
• Light intesntiy=add artifical lighting
• Temperature=use heaters to increase until optimum is reached
• Water=irrigation/sprinkler system
• Mineral ions=fertilisers (organic or inorganic)