Question

Carbon dioxide is fixed in
(a) Light reaction
(b) Dark reaction
(b) Photorespiration
(d) Spliting of water

Answer 1

Answer:

carbon di oxide is fixed in the dark reaction.

Explanation:

photosynthesis consist of light reaction and dark reaction. Dark reaction occur in the stroma of chloroplast and is light independent.Dark reaction helps in the carbon di oxide fixation by utillizing ATP and NADPH formed in the light reaction to generate glucose.

           The carbon di oxide in the ist step reacts with Ribulose bis phosphate to form phosphoglyceric acid(PGA).PGA then carry out the further reaction such as formation of Phosphoglyceraldehyde(PGALD) and regeneration of Ribulose bis phosphate(RUBP).

Answer 2

Carbon dioxide is fixed in Dark Reaction.

Option B

Explanation:

• Dark reaction is second step of photosynthesis. It is the step that has a series of enzymatic reactions.
• The main reaction enzyme is the RuBisCO which is "Ribulose Bisphosphate Carboxylase Oxygenase".
• This enzyme reacts with ribulose 1,5 phosphate and carbon dioxide, to produce two molecules of glyceraldehyde 3 phosphate.
• This is the step of carbon dioxide fixation in the living world. Thus, dark phase uses the products of light reaction and uses them to produce the glucose.