Describe the ultrastructure of a chloroplast.

Explanation

Structure of Chloroplast :

Chloroplasts are green plastids containing green pigment called chlorophyll.
Chloroplasts are oval shaped organelles having a diameter of 2-10 micrometer and a thickness of 1- 2 micrometer.
(i) Envelope :
Chloroplast envelope has outer and inner membranes which is seperated by intermembrane space.
(ii) Stroma :
Matrix present inside to the membrane is called stroma.
It contains DNA, 70 S ribosomes and other molecules required for protein synthesis.
(iii) Thylakoids :
It consists of thylakoid membrane that encloses thylakoid lumen.
(iv) Grana : Some of the thylakoids are arranged in the form of discs stacked one above the other. These stacks are termed as grana, they are interconnected to each other by membranous lamellae called Fret channels.