Photosynthesis in Higher Plants

Question 1

F. Blackman

Answer 1

• Indicated that photosynthesis is not only a photochemical reaction but also a biochemical reaction.
• Propounded the ‘Principle of Limiting Factors’

Question 2

Robin Hill

Answer 2

Demonstrated photolysis of water by isolated chloroplasts in the presence of suitable electron acceptor

Question 3

M. Calvin

Answer 3

Traced the path of carbon in photosynthesis and established the C₃ cycle.

Question 4

Arnon

Answer 4

Discovered photophosphorylation

Question 5

M.D. Hatch and Roger Slack

Answer 5

Reported the C₄ pathway for CO₂ fixation in certain tropical grasses.

Question 6

Overall reaction in photosynthesis

Answer 6

6CO₂ + 6H₂O + light energy —> C₆H₁₂O₆ + 6O₂ + 6H₂O

Question 7

Action spectrum

Answer 7

Rate of photosynthesis at different wavelengths of light

Question 8

Absorption spectrum

Answer 8

Amount of light absorbed by a pigment at different wavelengths

Question 9

Chlorophyll a

Answer 9

C₅₅H₇₂O₅N₄Mg

Question 10

Chlorophyll b

Answer 10

C₅₅H₇₀O₆N₄Mg

Question 11

Carotene

Answer 11

C₄₀H₅₆

Question 12

Xanthophyll

Answer 12

C₄₀H₅₆O₂

Question 13

Materials used and produced in cyclic photophosphorylation

Answer 13

Used:
2 photons
1 ADP
1 phosphate group

Produced:
1 ATP

Question 14

Materials used and produced in non-cyclic photophosphorylation

Answer 14

Used:

• 4 photons
• 1 ADP
• 1 phosphate group
• 1 H₂O
• 1 NADP⁺

Produced:

• 1 NADPH + H⁺
• 1 ATP
• 1/2 O₂