Question

In what parts of the chloroplast does photosynthesis take place?

Answer 1

Photosynthesis occurs in granum and stroma parts of chloroplast.

Explanation:

Chloroplast is an organelle covered by double membrane. Inner membrane is folded inside to form lamellae. The lamellae are stacked one above the other to from granum. There are many grana in a single chloroplast. The remaining matrix consisting of cytoplasm is termed stroma. In the stroma are present other cytoplasmic inclusions like fragments of DNA and ribosome, etc.

Photosynthesis occurs in 2 steps:
1. Hill's reaction or Light reaction: It occurs in presence of light in granum part of chloroplast.

2. Dark reaction or Blackmann's reaction: It does not require light directly, occuring irrespective of presence or absence of light. However, it is dependent upon the end products of light reaction. it occurs in stroma part of chloroplast.

The answer may be spplemented by viewing the diagram of electron microscopic structure of chloroplast from any book one may have, covering photosynthesis.