Photosynthesis

Question 1

What are the advantages of using imobilised cells

Answer 1

Immobilized cells can be reused reducing cost, product is more pure.

Question 2

What is photosynthesis

Answer 2

The way plants make their own food using light energy

Question 3

Define autotroph and heterotroph

Answer 3

Autotroph- an organism that can make their own food
Heterotroph- an organism that cannot make their own food

Question 4

Name the sources that cause photosynthesis to occur

Answer 4

Light- sun or artificial light in greenhouses. Light is trapped by many pigments that can absorb light at different wavelength
- carbon dioxide- co2 diffuses into leaf through stomata, internal plant produces co2 during respiration.
Water- absorbed from soil by roots

Question 5

Describe the light stage of photosynthesis

Answer 5

-defendant on light
-takes place in granum of chloroplast
- energy from light is passed onto electrons and energizes them.
- electrons pass through one of 2 pathways.
Pathway 1- electrons leave reaction center chlorophyll and are returned to chloroplast.
- energy is released and trappe to form ATP.
Pathway 2- electrons leave reaction center chlorophyll but different electrons return.
Photolysis of water- water is split to form electrons, protons and oxygen.
- NADPH and ATP. Are made- move on to dark stage.

Question 6

Describe what happens in the dark stage of photosynthesis

Answer 6

Occurs in stromatolites of chloroplast.
Controlled by enzymes.
Carbon dioxide from air or respiration joins with NADPH and ATP to form glucose molecule.
NADPH supplies electrons
NADPH—->NADP++H++2E-
ATP provides energy,
ATP—->ADP+P+ENERGY
Reduction reaction (carbon dioxide is reduced to glucose= electrons are added)

Question 7

What are the factors affecting photosynthesis

Answer 7

Light intensity
Co2 concentration

Question 8

What part of the plant does photosynthesis take place in

Answer 8

Chloroplasts.

Question 9

What are the products of splitting water

Answer 9

Protons, electrons oxygen

Question 10

What happens to the trapped energy in photosynthesis

Answer 10

Forms ATP

Question 11

Explain pathway 1 and 2 for electron flow

Answer 11

Pathway1- electrons leave reaction centre chlorophyll and are returned to chloroplast, energy is released and trapped to form atp
Pathway2- electrons leave reaction centre chlorophyll but different electrons return.
Photolysis of water, water is split to form electrons protons and oxygen.
NADPH and atp are made

Question 12

Name a substance which absorbs light energy for photosynthesis

Answer 12

Chlorophyll