Question

Explain the Dark and Light Phase of Photosynthesis.Explain it for 5 marks​

Answer 1

Answer:

Photosynthesis begins with the light reaction which is carried out only during the day in the presence of sunlight. In plants, the light-dependent reaction takes place in the thylakoid membranes of chloroplasts. The Grana, membrane-bound sacs like structures present inside the thylakoids functions by gathering light and is called as photosystems. These photosystems have large complexes of pigment and proteins molecules present within the plant cells which plays the primary role during the process of light reactions. There are two types of photosystems: photosystem I and photosystem II.

Under the light-dependent reactions, the light energy is converted to ATP and NADPH which are used in the second phase of photosynthesis. During the light reactions, ATP and NADPH are generated by two electron transport chains, water is used and oxygen is produced.

The chemical equation in the light reaction can be reduced to:

2H2O + 2NADP+ + 3ADP + 3Pi → O2 + 2NADPH + 3ATPxplanation:

Answer 2

Answer:light rxn occurs in grana

In light phase includes

Light absorption

Water splitting

Oxygen release

Formation of high energy chemical intermediates, ATP and NADPH

Dark occurs in stroma

Explanation:C3 cycle

C4 cycle

CAM pathway

Photorespiration