Photosynthesis

Question 1

Why must water potentials be the same in DCPIP experiment

Answer 1

Same water potential so osmosis does not occurr so organelle does not shrink or burst

Question 2

What happens in the light dependent reaction?

Answer 2

Light energy is absorbed by chlorophyll and some of this energy is transferred to chemical energy in ATP. NADPH is produced

Question 3

What happens in the calvin cycle?

Answer 3

RuBP to Glycerate 3 phosphate to triose phosphate back to RuBP

Question 4

What is a thylakoid?

Answer 4

Disc shaped membrane, membrane bound structures found inside chloroplasts

Question 5

What is a grana?

Answer 5

Groups of thylakoids arranged in stacks

Question 6

What happens in photo ionisation?

Answer 6

The process by which a chlorophyll molecule becomes positively charged as a result of losing two electrons when it absorbs light

Question 7

What is the electron transfer chain?

Answer 7

A series of electron carriers arranged within a membrane that can accept and then pass on electrons

Question 8

What are the limiting factors of photosynthesis?

Answer 8

Light intensity
Carbon dioxide concentration
Temperature
Availability of water in soil

Question 9

First step of light independent reaction?

Answer 9

Carbon dioxide reacts with RuBP to form 2 molecules of glycerate 3-phosphate

Question 10

What is the first stage of light independent reaction catalysed by?

Answer 10

Rubisco

Question 11

2nd stage of light independent reaction?

Answer 11

GP reduced to triose phosphate. This is a reduction reaction

Question 12

What does second stage of light dependent reaction require?

Answer 12

Reduced NADP and ATP

Question 13

What is NADP used for in the light independent reaction?

Answer 13

To reduced GP

Question 14

What is ATP used for in the light independent reaction?

Answer 14

To provide additional energy for the reaction

Question 15

What are some substances that triose phosphate is converted into?

Answer 15

Sucrose for transport
Cellulose for storage
Amino acids

Question 16

Most triose phosphate is converted into glucose, what is this glucose used for?

Answer 16

Respiratory substrate or to regenerate more RuBP

Question 17

Describe inner membrane of a chloroplast?

Answer 17

Folded into lamallae
One granum consists of several stacked thylakoids
Between the granum is the intergranal lamalae

Question 18

Describe chloropast adaptations?

Answer 18

Many grana provide a large surface area for photosynthetic pigments
Proteins embedded into grana hold photosystems in place

Question 19

How does the light dependent stage of photosynthesis start?

Answer 19

Proton hits a chlorophyll molecule

Question 20

How many carbons does RuBP have?

Answer 20

5

Question 21

How are 2 molecules of glycerate 3 phosphate formed?

Answer 21

CO2 combined with RuBP with the enzyme rubisco

Question 22

Where is one carbon lost is the calvin cycle?

Answer 22

2x triose phosphate to RuBP

Question 23

What is the lost carbon atom used for in the carbon cycle?

Answer 23

To make useful products

Question 24

What is a waste product of photosynthesis>

Answer 24

Water