Name two cell-organelles that are double membrane-bound. What are the characteristics of these two organelles? State their functions and draw labelled diagrams of both.

(N/A) Mitochondria and chloroplasts are the two organelles that are double-membrane-bound.
Characteristics of the mitochondria:
Mitochondria are double-membrane-bound structures. The membrane is divided into inner and outer membranes,creating two aqueous compartments: the outer and inner compartments. The outer membrane is very porous,while the inner membrane is deeply folded into structures known as cristae. Cristae increase the surface area for $ATP$-generating chemical reactions. Mitochondria contain their own $DNA$ and ribosomes,allowing them to synthesize their own proteins,which is why they are considered semi-autonomous organelles.
Characteristics of chloroplasts:
Chloroplasts are double-membrane-bound structures divided into two distinct regions:
$(i)$ Grana: Stacks of flattened,disc-like membranous sacs called thylakoids,which contain chlorophyll. Adjacent grana are connected by membranous tubules called stroma lamellae.
$(ii)$ Stroma: $A$ homogenous fluid in which grana are embedded. It contains enzymes for carbohydrate and protein synthesis,as well as its own $DNA$ and ribosomes.
Functions of the mitochondria:
$(i)$ They are the sites for aerobic cellular respiration.
$(ii)$ They provide energy in the form of $ATP$ for all vital cellular activities.
$(iii)$ They act as semi-autonomous organelles due to the presence of their own $DNA$ and ribosomes.
$(iv)$ They contain enzymes required for the synthesis of various chemicals like fatty acids and amino acids.
Functions of chloroplasts:
$(i)$ They trap solar energy and utilize it for manufacturing food for plants through photosynthesis.
$(ii)$ They contain enzymes required for the synthesis of carbohydrates and proteins.