3.2 Photosynthesis

Question 1

Chloroplasts

Answer 1

• Light trapping organelles found in the cells of the leaf and stem
• Most chloroplasts found in the palisade mesophyll cells

Question 2

How are Chloroplasts transducers?

Answer 2

They convert the light energy of photons into chemical energy as ATP

Question 3

Photosynthetic pigments

Answer 3

Absorb photons at different wavelengths of light and begin its conversion to storable chemical energy:

• Chlorophylls
• Carotenoids

Question 4

Chlorophylls

Answer 4

• Chlorophyll a
• Chlorophyll b

They absorb photons of light in the BLUE-VIOLET and RED regions of the light spectrum

Question 5

Carotenoids (Accessory pigments)

Answer 5

• β-carotene
• Xanthophyll

They absorb light in the BLUE-VIOLET region of the spectrum

Question 6

Photosystems

Answer 6

• Antenna complex (cluster of photosynthetic pigments)
• Reaction centre (Two Chlorophyll a molecules and an electron acceptor molecule)

Question 7

Photosystem I

Answer 7

• 2 chlorophyll a molecules at its reaction centre with an absorption peak of 700nm
• Reaction centre of PS I is called P700

Question 8

Photosystem II

Answer 8

• 2 chlorophyll a molecules at its reaction centre with an absorption peak of 680nm
• Reaction centre of PS II is called P680

Question 9

LDS of Photosynthesis

Answer 9

Photophosphorylation: The synthesis of ATP using energy from photons of light

Photolysis: The splitting of water to form (2H+) + (2e-) + 1/2(O2)

The reduction of NADP: NADP is reduced to form reduced NADP

Question 10

Photophosphorylation

Answer 10

The addition of an inorganic phosphate ion to ADP to form ATP