Structure of chloroplast

i. In plants, chloroplast is found mainly in mesophyll of leaf.

ii. Chloroplast is lens shaped but it can also be oval, spherical, discoid or ribbon like. 

iii. A cell may contain single large chloroplast as in Chlamydomonas (type green algae) or there can be 20 to 40 chloroplasts per cell as seen in mesophyll cells(makes mesophyll layer in plant leaves). 

iv. Chloroplasts contain green pigment called chlorophyll along with other enzymes that help in production of sugar by photosynthesis.

V. Inner membrane of double membraned chloroplast is comparatively less permeable.

vi. Inside the cavity of inner membrane, there is another set of membranous sacs called thylakoids.

vii. Thylakoids are arranged in the form of stacks called grana (singular: granum).

viii. The grana are connected to each other by means of membranous tubules called stroma lamellae. 

ix. Space outside thylakoids is filled with stroma.

X. The stroma and the space inside thylakoids contain various enzymes essential for photosynthesis.

xi. Stroma of chloroplast contains DNA and ribosomes (70S).