Describe the ultrastructure of a chloroplast.

Explanation

(a) Ultra Structure of a Chloroplast.

(b) Structure and function of Chloroplast. Chloroplasts are green plastids, containing the green pigment called Chlorophyll. It has the following structures:
(i) Envelope: It has outer and inner membranes, which are separated by intermembrane space.
(ii) Stroma: Matrix present inside to the membrane is called stroma, which contains DNA, 70 S ribosomes and other molecules needed for protein synthesis.
(iii) Thylakoids: It consists of thylakoid membrane that encloses thylakoid lumen. Thylakoid forms a stack of disc like structures called granum.
(iv) Grana: Some of the thylakoids are arranged in the form of discs, stacked one above the other called grana. These stacks are termed as grana, they are interconnected to each other by membranous lamellae called Fret channels.
Functions:
1. Photosynthesis 2. Storage of starch 3. Synthesis of fatty acids 4. Storage of lipids 5. Formation of chloroplasts.